CN101124353A

CN101124353A - Method and apparatus for growing a group (III) metal nitride film and a group (III) metal nitride film

Info

Publication number: CN101124353A
Application number: CNA2005800394623A
Authority: CN
Inventors: K·S·A·布彻; M-P·F·温特伯特埃普富凯; P·P-T·陈; J·L·P·坦恩哈韦; D·I·约翰逊
Original assignee: Gallium Enterprises Pty Ltd
Current assignee: Gallium Enterprises Pty Ltd
Priority date: 2004-09-27
Filing date: 2005-09-27
Publication date: 2008-02-13
Anticipated expiration: 2025-09-27
Also published as: CN101124353B; ZA200703117B

Abstract

A process and apparatus for growing a group (III) metal nitride film by remote plasma enhanced chemical vapour deposition are described. The process comprises heating an object selected from the group consisting of a substrate and a substrate comprising a buffer layer in a growth chamber to a temperature in the range of from about 400 DEG C to o about 750 DEG C, producing active neutral nitrogen species in a nitrogen plasma remotely located from the growth chamber and transferring the active neutral nitrogen species to the growth chamber. A reaction mixture is formed in the growth chamber, the reaction mixture containing a species of a group (III) metal that is capable of reacting with the nitrogen species so as to form a group (III) metal nitride film and a film of group (III) s metal nitride is formed on the heated object under conditions whereby the film is suitable for device purposes. Also described is a group (III) metal nitride film which exhibits an oxygen concentration below 1.6 atomic%.

Description

Method and apparatus and (III) family metal nitride film of growth regulation (III) family metal nitride film

Technical field

The growth for Thin Film that the present invention relates to gan, indium nitride and aluminium nitride film or make by the alloy of these materials.In particular, the present invention relates to a kind of use remote plasma and strengthen the method and apparatus of vapour deposition (RPECVD) gallium nitride film growth, wherein from the electric neutrality of the nitrogen plasma of long-range generation but chemically active chemical species can be imported in the growth room of gallium nitride film growth.The present invention also prolongs and a kind of method that reduces the gallium nitride film damage in the gallium nitride film process of growth, and prolongs and a kind of method that makes sealed vessel (containment vessel) passivation of being made by aluminium, quartz or fused quartz.The invention still further relates to heating.In particular, the present invention relates to a kind of device that in severe environment, material is heated to comparatively high temps.

Background technology

Gan is that a kind of being widely used in made indigo plant, purple and the transistorized material of white light emitting diode, ultraviolet rays detector and High-Power Microwave.

Because gan is applicable to reality and potential purposes in the less energy-consumption device of a large amount of purposes in manufacturing, gallium nitride film receives great concern.

Gallium nitride film can be grown with multitude of different ways, comprises molecular beam epitaxy (MBE) method and Organometallic chemical vapor deposition (MOCVD) method.MOCVD selects to be used to the depositing of thin film method that LED obtains enough quality of producing.

Yet for the growth of gallium nitride film, the shortcoming of mocvd method is that it must be at about 1000 ℃ temperature operation.The material (as synthetic sapphire) that only can bear relatively-high temperature can make in this way.

It is another kind of growth method that remote plasma is strengthened chemical vapour deposition (RPECVD), and it can be used in growth regulation (III) family metal nitride film.When the film that will grow is gan, the RPECVD technology can use about 600 ℃ to about 680 ℃ growth temperature, to compare this temperature quite low with the growth temperature of MOCVD method, and can reduce installation cost.Another advantage of RPECVD method is to use the responsive to temperature type substrate material such as the zinc oxide of lattice and the tightr coupling of GaN.Though because plasma source is away from substrate, RPECVD is widely regarded as the technology of the species damage film of avoiding producing in the plasma body, but the inventor has been found that, by this method Sheng Chang film can by in addition low-energy relatively species (that is, in using the situation of nitrogen plasma less than 14.5eV) major injury.Although the damage of when using RPECVD, having avoided coming autoionization particulate and high-energy electron, but result as energy rapid decay in the short range of plasma source, if the energy that low-energy relatively active neutral nitrogen kind had that arrives substrate is higher than the intensity of Ga-N key (it is 2.2eV), then it still can cause damage.This damage can show as that nitrogen-atoms is lost from film or gallium atom and nitrogen-atoms are ejected and are incorporated other not preferred lattice sites subsequently into from its preferred lattice sites.

Therefore, when using the RPECVD growing technology, need further to reduce the energy of the active neutral nitrogen kind (active neutral nigrogen species) that arrives substrate.Considerable work has been carried out in following aspect: the crystallographic dimension in the GaN film is separated [I] with oxygen; Use ZnO as the recrystallization prospect [2] of buffer layer to GaN; And to the detailed contrast [3] of the characteristic of Grown GaN on quartzy and the Sapphire Substrate.(the room temperature transport property of this involuntary doped n type material is 100-200cm can be comparable to the early stage MBE material made from involuntary doped n type material growth by the RPECVD method in conjunction with the early stage polycrystalline material of laser CVD method manufacturing ²/ Vs[4], and carrier concn is about 10 ¹⁶Cm ^-3).

In PCT/AU2003/000598, a kind of method of making rich gallium gallium nitride film has been described.This method about 480 ℃ to about 900 ℃ growth temperatures and oxygen partial pressure wherein less than 10 ^-4Carry out in the atmosphere of-Torr.Although low-down oxygen partial pressure has helped to make the metal nitride film with improvement quality in the described method of aforementioned application, low like this oxygen partial pressure need reduce system pressure usually to realize low oxygen partial pressure in process of growth.

The shortcoming of traditional RPECVD method is, (even drops to about 10 by the oxygen that still is present in after the exhaust in the system ^-6To 10 ^-8The pressure of foundation of Torr) and the caused oxygen contamination of Sauerstoffatom that discharges from the quartz that is used for the seal protection plasma body in the method or alumiseal protection wall of container and tube wall.This has just shown a problem, and promptly this Sauerstoffatom mixes in the gallium nitride film easily, makes film have unwanted characteristic.Oxygen is a kind of doping agent in the gallium nitride film, but also may produce high-caliber separation in the temperature that is used for RPECVD in process of growth.When the doping of oxygen in gallium nitride film was uncontrollable, its concentration may surpass the level can tolerate or need, this level depend on whether need to mix a certain amount of oxygen mixes or even its to exist with very low concentration all be unwanted.Even when electronic carrier concentration is very low, since automatic compensation mechanism, the influence that the specific conductivity of film may be existed by oxygen, and this can make specific conductivity and electronic migration become very low.

Oxygen contamination also may cause crystalline size little or under specific growth conditions even form amorphous gallium nitride.In thin film growth process, exist low-level background oxygen (backgroundoxygen) to allow in thin film growth process by control input impurity gas on the specification requirement level that is horizontally set on device with hotchpotch.This has guaranteed that also the crystalline size is not subjected to the isolating restriction of oxygen.

When the surface of sealed vessel of making by aluminium, quartz or silicon-dioxide or sealed tube during with the high energy nitrogen ion of a part that forms nitrogen plasma (obtaining when using the RPECVD method) bombardment, because nitrogen ionic high-energy, some the chemically combined Sauerstoffatoms in sealed vessel or the sealed tube surface are released or expel out.This may cause between the dangling bonds of vessel surface place generation and nitrogen ion chemical reaction taking place.This chemical reaction depends on the type of plasma body and the material type of sealed vessel or sealed tube naturally.This reaction can be regarded as replacement(metathesis)reaction, wherein removes deoxidation from the structure of container, and is replaced into nitrogen.

Butcher; people such as K S A have reported the research for the possibility of seal protection container that makes quartzy and aluminum and pipe passivation; referring to Studies of the Plasma Related OxygenContamination of Gallium Nitride Grown by Remote Plasma EnhancedChemical Vapour Deposition (strengthening the research of the oxygen contamination relevant of the gan of chemical vapour deposition growth by remote plasma) with plasma body; Phys.Stat.Sol. (c) No1,156-160 (2002).In this article, the author has described a kind of method of handling alumiseal container or sealed tube, wherein alumiseal container or sealed tube are handled about 24 hours to several days long period in nitrogen or ammonia plasma treatment, and the treatment time is depended on the type of using needed plasma body subsequently.When using ammonia plasma treatment processing vessel or pipe, some alumina molecules on container or the tube surface are transformed into aluminium alkane (AlH ₃), this is a kind of unsettled species, its rapid decay in air forms aluminum oxide and hydrogen.When using nitrogen plasma treatment container or pipe, some alumina molecules on container or the tube surface change aluminium nitride (AlN) into, and this has limited the further evolution of taking the oxygen species.Yet in air atmosphere, aln layer also can change aluminum oxide and volatile gases product such as hydrogen into through after a while, has to repeat this treating processes like this before each gallium nitride film growth.The conclusion of people's such as aforementioned Butcher report is that by using the gallium nitride film of quartzy sealed tube or microwave window growth, even by making nitrogen plasma by wherein carrying out some pre-treatment, oxygen contamination also is inevitable.Consider fused quartz and quartzy chemical similarity, expect that same situation also can occur in the fused quartz tube.Thinking that quartz and fused quartz are not suitable for carrying out the reason of passivation can be owing to the chemical reaction that is considered to take place between high energy nitrogen ion and silicon-dioxide, and this reaction can be simplified as follows:

SiO _{2 (solids)}+ N _{2 (plasma bodys)}---Si _{O (gas)}+ N ₂O _(gas)(1)

As can be seen, two kinds of reaction product all are gasiform from equation (1).These gaseous product are blown away by nitrogen plasma, and like this, more silicon-dioxide are exposed to nitrogen plasma.

Therefore, need a kind of method and apparatus of gallium nitride film growth, wherein the oxygen contamination of gallium nitride film is reduced to minimum level.

In the RPECVD system, under the partial vacuum in the growth room, use from the reaction mixture of reactant such as ammonia (and/or nitrogen) and the trimethyl-gallium metal refining nitride metal nitride film of growing.Film is grown on the plate-like substrate that is positioned on the swiveling ring.Use fixed heater, from the below heated substrate.Long-range generation nitrogen plasma, and with in its adding growth room.In the situation of using molecular beam epitaxy (MBE), the pressure of growing metal nitride film can be low to moderate 10 ^-5Torr, and for RPECVD, pressure can be about 0.1-10 Torr.

Substrate is positioned at well heater top about 2 to 3mm.According to employed technology, growth temperature can be about 900 ℃ to about 1000 ℃, perhaps about 500 ℃ to about 1000 ℃.But for reach about 650 ℃ expection growth temperature on substrate, well heater must be in much higher temperature work, and like this, heat can be radiated on the substrate from the below.Therefore, must be unrare in the situation of about 1400 ℃ temperature operation well heater.The conventional well heater of the class used in heated substrate comprises heating unit or is tungsten or the thread filament of tantalum metal of about 0.5mm by being wrapped in the diameter that its edge has on the plate-like ceramic bases of recess.

Owing to used plasma body, the environment that metal nitride is grown contains the reducing atmosphere of nitrogen-atoms typically, and this atmosphere is very abominable for building material.WO2003/097532 has described the method that a kind of RPECVD of use method is made rich gallium gallium nitride film.This application is hereby incorporated by document.In WO 2003/097532 described method, the pressure that uses in the growth room is high more, and condition is abominable more.When growing system was adjusted to aforementioned working temperature and abominable atmosphere surrounding, aforementioned conventional well heater possibility even the stage before growth just be damaged.

The conventional well heater that comprises the resistance wire of making by tungsten or tantalum, when being exposed to the gas that in these systems, uses when (it comprises from the reactive nitrogen kind of plasma body with from the hydrogen of metallorganics), it can become fragile in employed growth temperature, and finished breaking.Perhaps, be deposited on contiguous loop or the metal between the coil when it because from metallorganics source gas or from himself more contingent evaporation when causing short circuit, it may burn.Because the embrittlement of metal and expansion or because evaporation of metals and condensing between the loop, resistance wire is ineffective, causes the overload of short circuit and short-circuited coil (winding).Therefore, the more reliable well heater of those well heaters that need be made by tungsten or tantalum than heating unit carries out the growth of metal nitride semiconductor to use MBE technology and RPECVD technology.

No. the 6th, 140,624, the conventional heater of another kind of type such as United States Patent (USP) are described.This well heater comprises dielectric matrix of being made by pyrolitic boron nitride and the pyrolytic graphite heating unit that is superimposed upon on this dielectric matrix.United States Patent (USP) the 5th, 343 has been described a kind of similar heating unit No. 022, this heating unit by boron nitride dielectric matrix (dielectric base) and wherein the pyrolytic graphite heating unit of parcel form.

At United States Patent (USP) the 4th, 777, in No. 022, a kind of extension heating unit and method have been described.This well heater comprises the resistance coil that is positioned at around the core, and this core comprises the hollow circuit cylinder tube portion of being made by boron nitride, pyrolitic boron nitride or pyrifolyte.

Comprise that the substrate of heating unit makes yet owing to used pyrolitic boron nitride and pyrolytic graphite, they at high temperature use the chemical vapour deposition technology, use suitable mask one deck to connect the growth of one deck ground, so the unusual costliness of these well heaters.Because it is expensive, for the manufacturing of the commercial metal nitride film that uses the RPECVD technology, these well heaters are non-remunerative economically.

Therefore, need a kind of cheap well heater, it can bear the abominable operational condition that runs at the RPECVD growing system that is used for the growing metal nitride.

Summary of the invention

An object of the present invention is to overcome or improve at least a above-mentioned shortcoming substantially, or satisfy at least a the demand.

The method of growing metal nitride film

According to a first aspect of the invention, provide a kind of method by remote plasma reinforcement chemical vapour deposition growth regulation (III) family metal nitride film, this method comprises the steps:

(a) will be selected from substrate and comprise buffer layer substrate target growth room's internal heating to about 400 ℃ to about 750 ℃ temperature range;

(b) in away from the nitrogen plasma of growth room, produce active neutral nitrogen kind;

(c) active neutral nitrogen kind is delivered in the growth room;

(d) in the growth room, form reaction mixture, contain (III) family metal species that can form (III) family metal nitride film in this reaction mixture with the reaction of nitrogen kind; And

(e) in that film is applicable under the condition of device purposes, on the target that is heated, form (III) family metal nitride film.

Substrate can comprise the buffer layer that is positioned on this substrate.Compare with the lattice of substrate, the lattice of buffer layer can more closely mate with the film lattice.Compare with (III) family metal nitride film that is applicable to the device purposes, (III) family metal nitride film that may not be suitable for the device purposes may have big defect concentration.

Compare with (III) family metal nitride film that is applicable to the device purposes, (III) family metal nitride film that may not be suitable for the device purposes may have low electronics or hole mobility.

Compare with (III) family metal nitride film that is applicable to the device purposes, (III) family metal nitride film that may not be suitable for the device purposes may have low-energy band gap.

Compare with (III) family metal nitride film that is applicable to the device purposes, (III) family metal nitride film that may not be suitable for the device purposes may have elevated oxygen level.

With in thin film growth process, can not compared by nitrogen kind badly damaged (III) family metal nitride film from nitrogen plasma, (III) family metal nitride film that may not be suitable for the device purposes may be badly damaged by nitrogen kind (nigrogen species) in thin film growth process.

Do not compare with there being the III-th family nitride film in substrate or upward growth of buffer layer (this substrate or buffer layer are just badly damaged by the nitrogen kind from nitrogen plasma before growth regulation (III) family metal nitride film), (III) family metal nitride film that may not be suitable for the device purposes can be gone up growth at substrate or buffer layer (this substrate or buffer layer are before badly damaged by the nitrogen kind from nitrogen plasma at growth regulation (III) family metal nitride film).

With in advance the pipe that is used to hold nitrogen plasma is carried out after the passivation III family metal nitride film of growth and compares, (III) family metal nitride film that may not be suitable for the device purposes may be grown in the situation of in advance the pipe that is used for holding nitrogen plasma not being carried out passivation.

(III) family metal nitride that has the nitrogen plasma growth that the nitrogen of suitable levels of impurities generates with use is compared, and (III) family metal nitride film that may not be suitable for the device purposes may be to use nitrogen plasma growth that nitrogen with excessive level impurity generates.

Compare with (III) family metal nitride film of pressure suitable in the growth room (this suitable pressure cause generating the metal nitride film that is applicable to the device purposes) growth down, (III) family metal nitride film that may not be suitable for the device purposes may be to grow under the pressure low excessively in the growth room.

Compare with (III) family metal nitride film that is applicable to the device purposes, (III) family metal nitride film that may not be suitable for the device purposes may be to grow in containing the atmosphere of high keto sectional pressure.

With compare as the semi-conductive III metal nitride film of device purposes that is applicable to, (III) family metal nitride film that may not be suitable for the device purposes may be an insulating.

Compare with (III) family metal nitride film that is applicable to the device purposes of can be unwanted other annealing steps, (III) family metal nitride film that may not be suitable for the device purposes may need other annealing steps.

(III) family metal nitride film that may not be suitable for the device purposes may be (III) family metal nitride film that does not show the crystallographic structure characteristic of (III) family metal nitride.

(III) family metal nitride film that goes for the device purposes can be (III) family metal nitride film that shows (III) family crystal of nitride of metal structural performance.

(III) family metal nitride film that may not be suitable for the device purposes can be following (III) family metal nitride film: wherein this film is grown on substrate or buffer layer, therefore has huge lattice mismatch (latticemismatch) between this film and substrate or buffer layer.

(III) family metal nitride film that goes for the device purposes can be following (III) family metal nitride film: wherein this film is grown on substrate or buffer layer, therefore has very little lattice mismatch or do not have lattice mismatch between this film and substrate or buffer layer.

(III) family metal nitride film that may not be suitable for the device purposes can be following (III) family metallic film: wherein this film shows columnar structure (M.A.Sanchez-GarciaE.Calleja, E.Monroy, FJ.Sanchez, F.Calle, E.Munoz and R.Beresford, J.Cryst.Growth, 183,23,1998).

(III) family metal nitride film that goes for the device purposes can be the film that wherein film does not show columnar structure.

The film that is applicable to the device purposes can further carry out procedure of processing, as doping, annealing etc.

Step (e) can comprise step (e1):

(e1) under the following conditions at the film that forms (III) family metal nitride on the target that is heated: this condition makes below the low 500meV of band gap of band gap than fixed (III) family metal nitride of measured film, and makes film be applicable to the device purposes.

Step (e) can comprise step (e2):

(e2) under the following conditions at the film that forms (III) family metal nitride on the target that is heated: this condition makes below the low 500meV of band gap of band gap than fixed (III) family metal nitride of measured film, and make film be applicable to the device purposes, wherein in described forming process, use to be selected from least a in the following condition:

(i) target in the growth room the position and nitrogen plasma leave the zone that produces nitrogen plasma the position between distance be about 20cm to about 25cm, wherein the pressure the growth room in is approximately between 1Torr and the about 15Torr;

(ii) the oxygen partial pressure in the growth room is less than 10 ^-4Torr;

(iii) the oxygen partial pressure in the growth room is 10 ^-4Torr to 10 ^-11In the scope of Torr;

(iv) the pressure in the growth room is approximately between 1Torr and the about 15Torr;

(v) the pressure in the growth room is approximately between 2Torr and the about 5Torr;

(vi) baffle plate or impeller are in this target with between Nitrogen plasma source at a distance; And

(vii) described target is positioned at the growth room, and the distance between itself and the nitrogen plasma at a distance is about 20cm to about 25cm.

This film can be specially adapted to form the equipment of LED for example or miscellaneous equipment.LED can be blue-ray LED or other coloured light LED or white light LEDs.LED can be GaN LED.LED can be the GaN blue-ray LED.

This target can be positioned at the growth room, and the distance between the exit end of the sealed tube that itself and nitrogen plasma form therein is that about 20cm is to about 25cm.When the distance between the outlet section of target and sealed tube when being about 20cm to about 25cm, the pressure in wherein can the growth room of growing metal nitride film can make this film be applicable to the device purposes.Position and distance sealed tube (containment tube) exit end between of target in the growth room can be less than about 20cm, perhaps and the distance between the sealed tube exit end can be greater than about 25cm.When target in the growth room the position and the distance between the sealed tube exit end less than about 20cm (for example, approximately between 20cm and the about 10cm, perhaps approximately between 20cm and the about 15cm, perhaps between 20cm and 17cm) time, pressure in wherein can the growth room of growing metal nitride film can make this film be applicable to the device purposes (in this case, pressure in the growth room may be higher than the pressure in the distance of film/target and the sealed tube exit end growth room approximately between 20cm and the 25cm time, so that reduce the damage of ionized nitrogen kind and neutral nitrogen kind to the film of on target, growing, for example, if 3-5 Torr is the convenient pressure in the growth room concerning the distance of 20cm-25cm, then concerning the distance of 20cm-17cm, 5-10Torr is suitable in the growth room, need determine by test although should recognize suitable working pressure range and optimum pressure).When target in the growth room the position and the distance between the sealed tube exit end when surpassing about 25cm (for example, approximately between 25cm and the about 50cm, perhaps approximately between 25cm and the about 40cm, perhaps between 25cm and 30cm, perhaps between 25cm and 28cm) time, pressure in wherein can the growth room of growing metal nitride film can make this film be applicable to the device purposes (in this case, pressure in the growth room may be identical or lower than it with the growth room's internal pressure when the distance between film/target and the sealed tube exit end is between about 20cm and 25cm, so that reduce the damage of ionized nitrogen kind and neutral nitrogen kind to film, for example, if 3-5Torr is the convenient pressure in the growth room for the distance of 20cm-25cm, then concerning the distance of 25cm-35cm, 1-3Torr is suitable in the growth room, need determine by test although should recognize suitable working pressure range and optimum pressure).

Baffle plate or impeller can be between target and sealed tube exit end.The position of baffle plate or impeller can be near near (for example, 0-10cm, 1-8cm, the 1-6cm) of sealed tube exit end.

Step (e) can comprise step (e3):

(e3) form the film of (III) family metal nitride on the target that is heated, the band gap of wherein measured film is lower by 70 to 40meV than the band gap of fixed (III) family metal nitride, and this film is applicable to the device purposes.

Step (e) can comprise step (e4):

(e4) form the film of (III) family metal nitride on the target that is heated, the band gap of wherein measured film is lower by 70 to 40meV than the band gap of fixed (III) family metal nitride, and this film is applicable to the device purposes.

Step (e) can comprise step (e5):

(e5) form the film of (III) family metal nitride under the following conditions on the target that is heated: this condition makes film to be semiconductor film and to be applicable to the device purposes, and wherein this metal is selected from the combination of combination, indium and aluminium of combination, gallium and indium of gallium, indium, gallium and aluminium and the combination of gallium and indium and aluminium.

Step (e) can comprise step (e6):

(e6) form the film of (III) family metal nitride under the following conditions on the target that is heated: this condition makes film to be semiconductor film and to be applicable to the device purposes, wherein this metal is selected from the combination of combination, indium and aluminium of combination, gallium and indium of gallium, indium, gallium and aluminium and the combination of gallium and indium and aluminium, wherein in described forming process, use to be selected from least a in the following condition:

(i) target in the growth room the position and nitrogen plasma leave the zone that produces nitrogen plasma the position between distance be about 20cm to about 25cm, and wherein the pressure in the growth room approximately between 1Torr and the about 15Torr;

(ii) the oxygen partial pressure in the growth room is less than 10 ^-4Torr;

(vii) position and the distance at a distance nitrogen plasma between of target in the growth room is that about 20cm is to about 25cm.

Step (e) can comprise step (e7)

(e7) form the film of (III) family metal nitride under the following conditions on the target that is heated: this condition makes the resistivity of film about 0.0001 and 10 ⁴Between the ohm.cm and make film be applicable to the device purposes, wherein this metal is selected from the combination of combination, indium and aluminium of combination, gallium and indium of gallium, indium, gallium and aluminium and the combination of gallium and indium and aluminium.

Step (e) can comprise step (e8):

(e8) form the film of (III) family metal nitride under the following conditions on the target that is heated: this condition makes the resistivity of film about 0.0001 and 10 ⁴Between the ohm.cm and make film be applicable to the device purposes, wherein this metal is selected from the combination of combination, indium and aluminium of combination, gallium and indium of gallium, indium, gallium and aluminium and the combination of gallium and indium and aluminium, wherein in described forming process, use to be selected from least a in the following condition:

(ii) the oxygen partial pressure in the growth room is less than 10 ^-4Torr;

(vi) baffle plate or impeller are between target and Nitrogen plasma source at a distance; And

Step (e) can comprise step (e9):

(e9) form the film of (III) family metal nitride under the following conditions on the target that is heated: this condition makes film show the crystallographic structure characteristic of (III) family metal nitride and is applicable to the device purposes.

Step (e) can comprise step (e10):

(e10) on the target that is heated, form the film of (III) family metal nitride, wherein this film shows the crystallographic structure characteristic of (III) family metal nitride, and this film is applicable to the device purposes, wherein in described forming process, use to be selected from least a in the following condition:

(ii) the oxygen partial pressure in the growth room is less than 10 ^-4Torr;

(v) the pressure in the growth room is approximately between 2Torr and about 5 Torr;

Step (e) can comprise step (e11):

(e11) form the film of (III) family metal nitride under the following conditions on the target that is heated: this condition makes film show oxygen concn less than 1.6 atom %, and wherein this film is applicable to the device purposes.

Step (e) can comprise step (e12):

(e12) on the target that is heated, form the film of (III) family metal nitride, wherein this film shows that oxygen concn is less than 1.6 atom %, and wherein this film is applicable to the device purposes, wherein in described forming process, uses to be selected from least a in the following condition:

(ii) the oxygen partial pressure in the growth room is less than 10 ^-4Torr;

(vii) target is that about 20cm is to about 25cm in the position and the distance between the nitrogen plasma at a distance of growth room.

Step (b) can comprise step (b1):

(b1) produce active neutral nitrogen kind in away from the nitrogen plasma of growth room, wherein this plasma body generates from nitrogen, and the impurity that comprises in this nitrogen is less than or equal to 10 parts/1,000,000,000 parts nitrogen.

Step (c) can comprise step (c1):

(c1) active neutral nitrogen kind is delivered in the growth room through sealed tube, described sealed tube comprises the pipe that is selected from silica tube (silica tube), silica tube (quartz tube) and boron nitride tube, and described pipe has internal surface.

In step (a) before, can carry out step (a '), step (a ') comprising:

(a ') contacts about 1 hour to 100 hours for some time at about 10mTorr with nitrogen plasma with at least a portion of sealed tube internal surface to the pressure of about 100 Torr, at least a portion of sealed tube internal surface is contacted the nitrogen ionic reaction to small part silicon-dioxide and the nitrogen plasma that makes in the sealed tube with nitrogen plasma, to the pressure of about 100Torr, change the species that do not discharge Sauerstoffatom or discharge less Sauerstoffatom at about 10mTorr into thereby make to small part silicon-dioxide.

Step (c) can comprise step (c2):

(c2) active neutral nitrogen kind is delivered in the growth room, makes active neutral nitrogen kind directly lead to the central zone of target along passage, the position of this passage becomes the angle of 45 degree to the right angle basically with the plane that comprises target.

According to an embodiment of the invention, a kind of method by remote plasma reinforcement chemical vapour deposition growth regulation (III) family metal nitride film is provided, this method comprises the steps:

-will be selected from substrate and comprise buffer layer substrate target growth room's internal heating to about 400 ℃ to about 750 ℃ temperature range;

-active neutral nitrogen the kind of generation in away from the nitrogen plasma of growth room;

-active neutral nitrogen kind is delivered in the growth room;

-in the growth room, form reaction mixture, contain (III) family metal species that can form (III) family metal nitride film in this reaction mixture with the reaction of nitrogen kind; And

-forming (III) family metal nitride film on the target that is heated under the following conditions: this condition makes below the low about 500meV of band gap of band gap than fixed (III) family metal nitride of measured film.

These conditions can comprise one or more the following conditions that are selected from: (i) pressure in the growth room; (ii) wherein, target in the growth room the position and nitrogen plasma leave the zone that produces nitrogen plasma the position between have certain distance; (iii) wherein baffle plate or impeller in target be used between the source of long-range generation nitrogen plasma; The (iv) temperature of target in the growth room; And (the v) oxygen partial pressure in the growth room, thus make below low about 500 meV of band gap of band gap than fixed (III) family metal nitride of measured film.

The band gap of measured film can be following than the low about 450meV of the band gap of fixed (III) family metal nitride, approximately 400meV is following, approximately 350meV is following, approximately 300meV is following, approximately 250meV is following, approximately 200meV is following, approximately 175meV is following, approximately 150meV is following, approximately 125meV is following, approximately 100meV is following or approximately below the 80meV.Measured band gap can hang down 500-400 than the band gap of fixed (III) family metal nitride, 500-300,500-200,500-100,500-80,500-60,500-50,500-40,500-30,500-20,500-10,450-400,400-300,400-200,400-100,400-80,400-60,400-50,400-40,400-30,400-20,400-10,300-250,300-200,300-100,300-80,300-60,300-50,300-40,300-30,300-20,300-10,250-210,250-200,250-100,250-80,250-60,250-50,250-40,250-30,250-20,250-10,200-175,200-150,200-125,200-100,200-80,200-70,200-60,200-40,200-30,200-10,150-120,150-100,150-90,150-80,150-60,150-50,150-40,150-30,150-20,150-10,100-90,100-80,100-70,100-60,100-50,100-40,100-30,100-20,100-10,75-70,75-60,75-50,75-40,75-30,75-20,75-10,65-60,65-50,65-40,65-30,65-20,65-10,60-40,55-40,55-45 or 53-47meV.

Measured band gap can be than the band gap low about 500,475,450,425,400,375,350,325,300,275,250,225,200,175,150,125,100,90,80,75,70,65,60,55,50,45,40,35,30,25,20,15,10 or the 5meV of fixed (III) family metal nitride.

In the process that forms (III) family metal nitride film, the pressure in the growth room can remain on, for example, and in about 0.1 to about 15Torr, 0.5 to 10Torr, 1 to 7Torr, 1.5 to 5Torr, 2 to 4Torr or 2.5 to 3.5Torr the scope.Oxygen partial pressure in the growth room can be less than 10 ^-2, 10 ^-3, 10 ^-4, 10 ^-5, 10 ^-6, 10 ^-7, 10 ^-8, 10 ^-9, 10 ^-10, 10 ^-11Or 10 ^-12Torr.

According to another implementation of the invention, provide a kind of method by remote plasma reinforcement chemical vapour deposition growth regulation (III) family metal nitride film, this method comprises the steps:

-active neutral nitrogen kind is delivered in the growth room;

-under certain pressure, on the target that is heated, form the film of (III) family metal nitride, below the low about 500meV of band gap of the band gap of wherein measured film than fixed (III) family metal nitride.

(III) family metal can be a gallium.

The plasma generating area that produces nitrogen plasma is left the position in the zone that produces nitrogen plasma and the distance between the target and the pressure in the growth room with respect to position, the nitrogen plasma of target can be as described below: the active neutral nitrogen kind that produces in plasma generating area that arrives target, average energy in thin film growth process less than or be substantially equal to the bond energy of (III) family metal-nitride of (III) family metal nitride, perhaps the average energy before the film growth less than or be substantially equal to the bond energy of buffer layer on the substrate.

The average energy of active neutral nitrogen kind can less than or be substantially equal to the bond energy of (III) family metal-nitride of (III) family metal nitride, but greater than the heat energy of substrate.

Active neutral nitrogen kind from nitrogen plasma can be the chemically active species of electric neutrality.In the situation of gan, by increase between position that nitrogen plasma leaves the zone that produces nitrogen plasma and the target distance with increase combining of growth room's internal pressure, can prevent from substantially in the process of gallium nitride film growth, to arrive substrate more than or equal to the chemically active species of the electric neutrality of about 2.2 eV from the average energy of nitrogen plasma.Nitrogen plasma leave the position in the zone that produces nitrogen plasma and the distance between the target be pressure in about 20 to 25cm, the growth room between about 2 Torr and about 4 Torr and baffle plate or impeller in target be used between the source of long-range generation nitrogen plasma, it is good that this has demonstrated aspect the growth of gallium nitride film work.

The increase nitrogen plasma leaves the position in the zone that produces nitrogen plasma and the pressure in distance between the target and the increase growth room increases the molecular impact number, this molecular impact is by from the electric neutrality chemically active species of plasma body and be in the collision that stands between the background gas species of thermal energy state, so the overall average energy of electric neutrality chemically active species has reduced.The electric neutrality chemically active species can be Nitrogen Atom in the situation of nitrogen.The reduction of this average energy must balance each other with the finite life of electric neutrality chemically active species, and the electric neutrality chemically active species formed non-reacted species with (III) family metal reaction before reacting to each other like this, and the latter can not participate in growth for Thin Film.

By using one or more baffle plate or impeller, average energy from nitrogen plasma can significantly reduction before it arrives substrate greater than the energy of the electric neutrality chemically active species of about 2.2 eV (in the situation of GaN, this is the average energy upper limit that need arrive the electric neutrality chemically active species of substrate in the process of GaN growth).Baffle plate or impeller have reduced the average energy of electric neutrality chemically active species by inducing the further collision with low-energy surface and other low energy species of gases.

In an embodiment relevant with the GaN film growth, before arriving target, can reduce its energy greater than the about electric neutrality chemically active species of 2.2eV from the average energy of nitrogen plasma: (i) the indoor pressure of control growing by following manner, (ii) select target and nitrogen plasma leave the suitable distance between the position in the zone that produces nitrogen plasma, and (iii) use one or more in target be used for baffle plate and/or impeller between the source of long-range generation nitrogen plasma simultaneously.

-active neutral nitrogen kind is delivered in the growth room;

-in the growth room, form reaction mixture, contain (III) family metal species that can form (III) family metal nitride film in this reaction mixture with the reaction of nitrogen kind, and

-be under the condition of semiconductor film making film, on the target that is heated, form metal nitride film, wherein this metal is selected from the combination of combination, indium and aluminium of combination, gallium and indium of gallium, indium, gallium and aluminium and the combination of gallium and indium and aluminium, and wherein this film is a semiconductor film.

Making film is that the condition of semiconductor film can comprise one or more the following conditions that are selected from: (i) pressure in the growth room; (ii) wherein target in the growth room the position and nitrogen plasma leave the zone that produces nitrogen plasma the position between have a segment distance; (iii) wherein baffle plate or impeller in target be used between the source of long-range generation nitrogen plasma; The (iv) temperature of target in the growth room; And (the v) oxygen partial pressure in the growth room.

Gan and indium nitride film with and each other with the situation of the alloy of itself and AlN in, the resistivity of film can be less than about 10 ⁴, 10 ³, 10 ², 10,1,0.1,0.01,0.001 or 0.0001 ohm.cm.

In the situation of gan and indium nitride film, the resistivity of film can be 10 ⁴-0.0001,10 ³-0.0001,10 ²-0.0001,10-0.0001,1-0.0001,0.1-0.0001,10 ⁴-0.001,10 ³-0.001,10 ²-0.001,10 ¹-0.001,1-0.001,0.1-0.001,0.01-0.001,0.05-0.001,10 ⁴-0.002,10 ³-0.002,10 ²-0.002,10 ¹-0.002, between 1-0.002,0.1-0.002,0.01-0.002 or the 0.05-0.002 ohm.cm.

The band gap of measured gallium nitride film can be than the band gap of fixed gan below low about 500 meV.

Oxygen partial pressure can be less than 10 ^-2, 10 ^-3, 10 ^-4, 10 ^-5, 10 ^-6, 10 ^-7, 10 ^-8, 10 ^-9, 10 ^-10, 10 ^-11Or 10 ^-12Torr.

-active neutral nitrogen kind is delivered in the growth room;

-on the target that is heated, forming (III) family metal nitride film under the following conditions: this condition makes film show the crystallographic structure characteristic of (III) family metal nitride.

Make film show that the crystallographic structure characteristic of (III) family metal nitride or the condition that (III) family crystal of nitride of metal is learned the X-line diffraction reflection characteristic of structural performance can comprise one or more the following conditions that are selected from: (i) pressure in the growth room; (ii) wherein target in the growth room the position and nitrogen plasma leave the zone that produces nitrogen plasma the position between have a segment distance; (iii) wherein baffle plate or impeller in target be used between the source of long-range generation nitrogen plasma; The (iv) temperature of target in the growth room; And (the v) oxygen partial pressure in the growth room.

The crystalline structure of film can be wurtzite (wurtzite) structure or cubic structure.Film can not be an amorphous membrance.(III) family metal nitride can comprise GaN, InN, AlN or its alloy, and can be wurtzite structure or cubic structure or the X-line diffraction reflection characteristic that shows wurtzite structure or cubic structure or its combination.(III) family metal nitride can comprise GaN, InN, AlN or its alloy, and can be wurtzite structure or the X-line diffraction reflection characteristic that shows the wurtzite structure feature of GaN, InN, AlN or its alloy.Measured film band gap can be than the band gap of fixed (III) family metal nitride below low about 500meV.Film can be semiconductor film (except being the insulating in the situation of AlN).

-active neutral nitrogen kind is delivered in the growth room;

-on the target that is heated, forming (III) family metal nitride film under the following conditions: this condition makes the oxygen concn of film demonstration less than 1.6 atom %.

This condition can comprise one or more the following conditions that are selected from: (i) pressure in the growth room; (ii) wherein target in the growth room the position and nitrogen plasma leave the zone that produces nitrogen plasma the position between have a segment distance; (iii) wherein baffle plate or impeller in target be used between the source of long-range generation nitrogen plasma; The (iv) temperature of target in the growth room; And (the v) oxygen partial pressure in the growth room, thus the oxygen concn that film is shown is lower than 1.6,1.5,1.4,1.3,1.2,1.1,1.0,0.9,0.8,0.7,0.6,0.5,0.4,0.3,0.2,0.1,0.075,0.05,0.038,0.030,0.010,0.007,0.005,0.003,0.0009,0.0007,0.0005,0.0003 or 0.0001 atom %.Oxygen partial pressure in the growth room can be less than 10 ^-2, 10 ^-3, 10 ^-4, 10 ^-5, 10 ^-6, 10 ^-7, 10 ^-8, 10 ^-9, 10 ^-10, 10 ^-1Or 10 ^-12Torr.Oxygen partial pressure in the growth room can be 10 ^-2-10 ^-12, 10 ^-2-10 ^-11, 10 ^-2-10 ^-12, 10 ^-2-10 ^-10, 10 ^-3-10 ^-12, 10 ^-3-10 ^-11, 10 ^-3-10 ^-10, 10 ^-4-10 ^-12, 10 ^-4-10 ^-11, 10 ^-4-10 ^-10, 10 ^-5-10 ^-12, 10 ^-5-10 ^-11, 10 ^-5-10 ^-10, 10 ^-6-10 ^-12, 10 ^-6-10 ^-11, 10 ^-6-10 ^-10, 10 ^-7-10 ^-12, 10 ^-7-10 ^-11, 10 ^-7-10 ^-10, 10 ^-8-10 ^-12, 10 ^-8-10 ^-11, 10 ^-8-10 ^-10, 10 ^-9-10 ^-12, 10 ^-9-10 ^-11, 10 ^-9-10 ^-10, 10 ^-10-10 ^-12, 10 ^-10-10 ^-11Or 10 ^-11-10 ^-12In the scope of Torr.The oxygen concn scope that this film shows can be 1.59-0.01,1.4-0.01,1.3-0.01,1.2-0.01,1.1-0.01,1-0.01,0.9-0.01,0.8-0.01,0.7-0.01,0.6-0.01,0.5-0.01,0.4-0.01,0.3-0.01,0.2-0.01,0.1-0.01,0.075-0.01,1.59-0.02,1.4-0.02,1.3-0.02,1.2-0.02,1.1-0.02,1-0.02,0.9-0.02,0.8-0.02,0.7-0.02,0.6-0.02,0.5-0.02,0.4-0.02,0.3-0.02,0.2-0.02,0.1-0.02,0.075-0.02,1.59-0.03,1.4-0.03,1.3-0.03,1.2-0.03,1.1-0.03,1-0.03,0.9-0.03,0.8-0.03,0.7-0.03,0.6-0.03,0.5-0.03,0.4-0.03,0.3-0.03,0.2-0.03,0.1-0.03,0.075-0.03,1.59-0.03 8,1.59-0.000 1,1.59-0.0009,1.59-0.001,1.59-0.003,1.59-0.005,1.59-0.009,1.59-0.01,1.0-0.038,1.0-0.0001,1.0-0.0009,1.0-0.001,1.0-0.003,1.0-0.005,1.0-0.009,1.0-0.01,0.5-0.038,0.5-0.0001,0.5-0.0009,0.5-0.001,0.5-0.003,0.5-0.005,0.5-0.009,0.5-0.01,0.1-0.038,0.1-0.0001,0.1-0.0009,0.1-0.001,0.1-0.003,0.1-0.005,0.1-0.009,0.1-0.01,0.05-0.038,0.05-0.0001,0.05-0.0009,0.05-0.001,0.05-0.003,0.05-0.005,0.05-0.009 or 0.05-0.01 atom %.This film can be the n type film that comprises n type hotchpotch.This film can be the p type film (in the situation of p type film, needing independent p type doping step) that comprises p type hotchpotch.Carrier concn in the film can be 10 ¹⁶-10 ²¹Carrier/cm ³, 10 ¹⁷-10 ²⁰Carrier/cm ³, 10 ¹⁷-10 ²¹Carrier/cm ³, 5 * 10 ¹⁷-10 ²¹Carrier/cm3,5 * 10 ¹⁷-10 ²⁰Carrier/cm ³, 5 * 10 ¹⁷-10 ¹⁹Carrier/cm ³, 10 ¹⁷-10 ¹⁸Carrier/cm ³, 10 ¹⁷-10 ¹⁹Carrier/cm ³, 7 * 10 ¹⁷-10 ¹⁹Carrier/cm ³, 10 ¹⁸-10 ²⁰Carrier/cm ³Or 10 ¹⁹-10 ²⁰Carrier/cm ³Scope in.Carrier concn can be donor or acceptor carrier concentration.This film goes for the device purposes.The oxygen concn of film can be measured by SIMS.

The present invention (for example also provides a kind of (III) family metal nitride film, the GaN film), wherein the oxygen concn of this film demonstration is lower than 1.6,1.5,1.4,1.3,1.2,1.1,1.0,0.9,0.8,0.7,0.6,0.5,0.4,0.3,0.2,0.1,0.075,0.05,0.038,0.030,0.010,0.007,0.005,0.003,0.0009,0.0007,0.0005,0.0003 or 0.0001 atom %.The oxygen concn scope that this film shows is 1.59-0.01,1.4-0.01,1.3-0.01,1.2-0.01,1.1-0.01,1-0.01,0.9-0.01,0.8-0.01,0.7-0.01,0.6-0.01,0.5-0.01,0.4-0.01,0.3-0.01,0.2-0.01,0.1-0.01,0.075-0.01,1.59-0.02,1.4-0.02,1.3-0.02,1.2-0.02,1.1-0.02,1-0.02,0.9-0.02,0.8-0.02,0.7-0.02,0.6-0.02,0.5-0.02,0.4-0.02,0.3-0.02,0.2-0.02,0.1-0.02,0.075-0.02,1.59-0.03,1.4-0.03,1.3-0.03,1.2-0.03,1.1-0.03,1-0.03,0.9-0.03,0.8-0.03,0.7-0.03,0.6-0.03,0.5-0.03,0.4-0.03,0.3-0.03,0.2-0.03,0.1-0.03,0.075-0.03,1.59-0.038,1.59-0.0001,1.59-0.0009,1.59-0.001,1.59-0.003,1.59-0.005,1.59-0.009,1.59-0.01,1.0-0.038,1.0-0.0001,1.0-0.0009,1.0-0.001,1.0-0.003,1.0-0.005,1.0-0.009,1.0-0.01,0.5-0.038,0.5-0.0001,0.5-0.0009,0.5-0.001,0.5-0.003,0.5-0.005,0.5-0.009,0.5-0.01,0.1-0.038,0.1-0.0001,0.1-0.0009,0.1-0.001,0.1-0.003,0.1-0.005,0.1-0.009,0.1-0.01,0.05-0.038,0.05-0.0001,0.05-0.0009,0.05-0.001,0.05-0.003,0.05-0.005,0.05-0.009 or 0.05-0.01 atom %.This film can be the n type film that comprises n type hotchpotch.This film can be the p type film (in the situation of p type film, needing independent p type doping step) that comprises p type hotchpotch.Carrier concn in the film can be 10 ¹⁶-10 ²¹Carrier/cm ³, 10 ¹⁷-10 ²⁰Carrier/cm ³, 10 ¹⁷-10 ²¹Carrier/cm ³, 5 * 10 ¹⁷-10 ²¹Carrier/cm ³, 5 * 10 ¹⁷-10 ²⁰Carrier/cm ³, 5 * 10 ¹⁷-10 ¹⁹Carrier/cm ³, 10 ¹⁷-10 ¹⁸Carrier/cm ³, 10 ¹⁷-10 ¹⁹Carrier/cm ³, 7 * 10 ¹⁷-10 ¹⁹Carrier/cm ³, 10 ¹⁸-10 ²⁰Carrier/cm ³Or 10 ¹⁹-10 ²⁰Carrier/cm ³Scope in.Carrier concn can be donor or acceptor carrier concentration.This film goes for the device purposes.The X-line diffraction reflection characteristic of the crystallographic structure characteristic of film demonstration (III) family metal nitride or the crystallographic structure characteristic of (III) family metal nitride.

The crystallographic structure that oxygen concn is lower than the film of 1.6 atom % can be wurtzite structure or cubic structure.This film is not an amorphous membrance.(III) family metal nitride can comprise GaN, InN, AlN or its alloy, and can be wurtzite structure or cubic structure or the X-line diffraction reflection characteristic that shows wurtzite structure or cubic structure or its combination.(III) family metal nitride can comprise GaN, InN, AlN or its alloy, and can be wurtzite structure or the X-line diffraction reflection characteristic that shows the wurtzite structure feature of GaN, InN, AlN or its alloy.Below the low about 500meV of band gap of the band gap of measured film than fixed (III) family metal nitride.Film can be semiconductor film (except being the insulating in the situation of AlN).

-in away from the nitrogen plasma of growth room, produce active neutral nitrogen kind, wherein this plasma body produces from following nitrogen: the impurity that comprises in this nitrogen is less than or equals 10 parts/1,000,000,000 parts nitrogen;

-active neutral nitrogen kind is delivered in the growth room;

-on the target that is heated, form (III) family metal nitride film.

Plasma body can produce from following nitrogen: the impurity that comprises in this nitrogen is less than or equals 9,8,7,6,5,4,3,2,1,0.7,0.5,0.3,0.1,0.08,0.05 parts/1,000,000,000 parts nitrogen.These umbers can be based on volume: volume, weight: weight, mole: mole or their combination.

Film can show the crystallographic structure characteristic of (III) family metal nitride or the X-line diffraction reflection characteristic that (III) family crystal of nitride of metal is learned structural performance.

The crystalline structure of film can be wurtzite structure or cubic structure.Film can not be an amorphous membrance.(III) family metal nitride can comprise GaN, InN, AlN or its alloy, and can be wurtzite structure or cubic structure or the X-line diffraction reflection characteristic that shows wurtzite structure or cubic structure or its combination.(III) family metal nitride can comprise GaN, InN, AlN or its alloy, and can be wurtzite structure or the X-line diffraction reflection characteristic that shows the wurtzite structure characteristic of GaN, InN, AlN or its alloy.The band gap of measured film can be than the band gap of fixed (III) family metal nitride below low about 500meV.Film can be semiconductor film (except being the insulating in the situation of AlN).The oxygen concn of film can be less than 1.59 atom %.

-active neutral nitrogen kind is delivered in the growth room through sealed tube, described sealed tube comprises silicone tube, silica tube or boron nitride tube, and has internal surface;

-on the target that is heated, form (III) family metal nitride film;

Wherein before this process or among, at least a portion of sealed tube internal surface can contact with nitrogen plasma, wherein this contact procedure is carried out about 1 hour to 100 hours time at about 10mTorr to the pressure of about 100Torr, this contact procedure makes at least a portion silicon-dioxide in the sealed tube and the nitrogen ionic reaction in the nitrogen plasma, does not discharge Sauerstoffatom or discharges the seldom species of Sauerstoffatom thereby at least a portion silicon-dioxide is changed into to the pressure of about 100Torr at about 10mTorr.

Substrate or the substrate that comprises buffer layer can use the heater heats according to seventh aspect present invention.

Plasma body can be from following nitrogen gas generation: the impurity that comprises this nitrogen is less than or equals 9,8,7,6,5,4,3,2,1,0.7,0.5,0.3,0.1,0.08,0.05 parts/1,000,000,000 parts nitrogen.These umbers can be based on volume: volume, weight: weight, mole: mole or its combination.

The crystallographic structure of film can be wurtzite structure or cubic structure.Film cannot be an amorphous membrance.(III) family metal nitride can comprise GaN, InN, AlN or its alloy, and can be wurtzite structure or cubic structure or the X-line diffraction reflection characteristic that shows wurtzite structure or cubic structure or its combination.(III) family metal nitride can comprise GaN, InN, AlN or its alloy, and can be wurtzite structure or the X-line diffraction reflection characteristic that shows the wurtzite structure characteristic of GaN, InN, AlN or its alloy.Below the low about 500meV of band gap of the band gap of measured film than fixed (III) family metal nitride.Film can be semiconductor film (except being the insulating in the situation of AlN).The oxygen concn of film can be less than 1.59 atom %.

Silicon-dioxide can change the nitride species into.

The substrate that is heated can rotate in the forming process of film.The substrate that is heated can rotate with the speed of rotation in the following ranges: this speed of rotation scope can be per minute 0.1 to 100,0.5-50,0.5-20,0.5-10,0.5-5,0.5-3,1-100,1-70,1-50,1-30,1-20,1-15,1-10,1-7,1-5,1-3 or 1-2 rotation.The substrate that is heated can be immobilized in the forming process of film.

In thin film growth process, arrive substrate the active neutral nitrogen kind (nitrogen species) that produces in plasma generating area average energy can less than or be substantially equal to the bond energy of (III) family metal nitride, perhaps the average energy of the active neutral nitrogen kind that in plasma generating area, produces that arrives substrate before the film growth can less than or be substantially equal to the bond energy of buffer layer on the substrate.Active neutral nitrogen kind can be a nitrogen-atoms.

The band gap of present fixed GaN (wurtzite-type) is about 3.4 eV, GaN (cube type) is about 3.1 eV, AlN (wurtzite-type) is about 6.2 eV, AlN (cube type) is about 5.2 eV, InN (wurtzite-type) is about 1.7 eV (can be low to moderate 0.65 eV although reported the variation of this band gap in the literature), and InN (cube type) is about 1.5 eV.Should recognize, report some variations of these numerical value in the literature, can be understood that better, fixed band gap may change according to the material behavior of InN, can obtain to be used for analyzing than the material of good quality.In the situation of ternary alloy and quad alloy, the fixed band gap of specified composition and crystalline structure can be determined from document.In the situation of GaAlN (wurtzite-type also can be described as hexangle type), for example, band gap will be according to the relative quantity of Ga in the alloy and Al and between 3.4 eV and 6.2 eV.

-active neutral nitrogen kind is delivered in the growth room;

-on the target that is heated, form (III) family metal nitride film,

Wherein active neutral nitrogen kind and/or reaction mixture directly lead to the central zone of target along passage, and the position of this passage becomes the angle of 45 degree to the right angle substantially with the plane that comprises substrate.

This method can be included in and form (III) family metal nitride film on the target that is heated, wherein active neutral nitrogen kind and/or reaction mixture directly lead to the central zone of target along passage, the position of this passage and angle in the plane that comprises target becomes following ranges basically: this angular range can be 50 degree to the right angle, 60 degree to the right angle, 70 degree to the right angle, 80 degree to the right angle, 85 spend to the right angle.

This method can be included in and form (III) family metal nitride film on the target that is heated, and wherein active neutral nitrogen kind and/or reaction mixture directly lead to the central zone of target along passage, and the position of this passage meets at right angles substantially with the plane that comprises target.

Following information is applied to first aspect and embodiment thereof:

Substrate can comprise one or more layers metal nitride film on the buffer layer that is arranged in base substrate (base substrate) or base substrate.

Base substrate can be selected from sapphire, silicon-dioxide, soda-lime glass, borosilicate glass, silicon, glass, synthetic sapphire, quartz and have and the tight crystalline material of the lattice of coupling of (III) family metal nitride.

(III) family metal species can be alkyl (III) family metal species, for example, and C ₁-C ₅Trialkyl-Di (III) family metal (wherein this metal is Ga, Al and/or In).

Gallium kind (gallium species) can be an alkyl gallium, for example, and C ₁-C ₅Trialkyl gallium, trimethyl-gallium, triethyl-gallium, ethyl dimethyl gallium or tripropyl gallium or their mixture.Indium kind (indium species) can be the alkyl indium, for example, and C ₁-C ₅Trialkyl indium, trimethyl indium, triethylindium, ethyl dimethyl indium or tripropyl indium or their mixture.Aluminium kind (aluminium species) can be an aluminum alkyls, for example, and C ₁-C ₅Trialkylaluminium, trimethyl aluminium, triethyl aluminum, ethyl dimethyl aluminium or tri-propyl aluminum or their mixture.Can use in alkyl gallium kind and/or alkyl indium kind and/or the aluminum alkyls kind at least two kinds mixture.

Temperature can be between about 400 ℃ and 680 ℃, between perhaps about 500 ℃ and about 670 ℃, between about 520 ℃ and 670 ℃, between perhaps about 530 ℃ and 670 ℃ or between about 540 ℃ and 670 ℃, between perhaps about 550 ℃ and 670 ℃, between perhaps about 560 ℃ and 670 ℃, between 570 ℃ and 670 ℃, between 580 ℃ and 670 ℃, between 590 ℃ and 670 ℃, between 600 ℃ and 670 ℃, between 610 ℃ and 670 ℃, between 620 ℃ and 670 ℃, between 630 ℃ and 660 ℃ or between 640 ℃ and 660 ℃.Temperature can be about 600,605,610,615,620,625,630,635,640,645,650,655 or 660 ℃.

In the process that (III) family metal nitride film forms, the pressure in the growth room can remain on about 0.1,0.5,1.0,1.5,2.0,2.1,2.2,2.3,2.4,2.5,2.6,2.7,2.8,2.9,3.0,3.1,3.2,3.3,3.4,3.5,3.6,3.7,3.8,3.9,4.1,4.2,4.3,4.4,4.5,4.6,4.7,4.8,4.9,5,5.5,6,6.5,7,7.5,8,8.5,9,9.5 or 10 Torr.

Substrate can be selected from sapphire, silicon-dioxide, soda-lime glass, borosilicate glass, silicon, glass, synthetic sapphire, quartz and have and the tight crystalline material of the lattice of coupling of (III) family metal nitride.In the situation of gan, substrate can be, for example, and zinc oxide, SiC, gan, HfN, AlGaN.Substrate can comprise the buffer layer of the zinc oxide that is positioned on the substrate, hafnium nitride, SiC etc.

When the film that will grow be selectable (III) family metal (for example, aluminium or indium) during nitride film, the active neutral nitrogen kind that produces in nitrogen plasma that arrives substrate can have following average energy: this average energy is less than or equal to the bond energy of (III) family metal nitride key.Metal nitride can comprise gan, indium nitride, aluminium nitride, aluminum gallium nitride, indium gallium nitride, indium nitride aluminium or Im-Ga-Al nitride.

A kind of gallium nitride film of the method acquisition of aforementioned any aspect defined according to the present invention is provided according to another implementation of the invention.

The gallium nitride film that is obtained can have the band gap of following measurement: measured band gap is following than low about 450 meV of the band gap of fixed (III) family metal nitride, about 400 meV are following, about 350 meV are following, about 300 meV are following, about 250 meV are following, about 200 meV are following, about 175 meV are following, approximately 150meV is following, about 125 meV are following, about 100 meV are following or below about 80 meV.Measured band gap can hang down 500-400 than the band gap of fixed (III) metal nitride, 500-300,500-200,500-100,500-80,500-60,500-50,500-40,500-30,500-20,500-10,450-400,400-300,400-200,400-100,400-80,400-60,400-50,400-40,400-30,400-20,400-10,300-250,300-200,300-100,300-80,300-60,300-50,300-40,300-30,300-20,300-10,250-210,250-200,250-100,250-80,250-60,250-50,250-40,250-30,250-20,250-10,200-175,200-150,200-125,200-100,200-80,200-70,200-60,200-40,200-30,200-10,150-120,150-100,150-90,150-80,150-60,150-50,150-40,150-30,150-20,150-10,100-90,100-80,100-70,100-60,100-50,100-40,100-30,100-20,100-10,75-70,75-60,75-50,75-40,75-30,75-20,75-10,65-60,65-50,65-40,65-30,65-20,65-10,60-40,55-40,55-45 or 53-47 meV.

Measured band gap can hang down about 500,475,450,425,400,375,350,325,300,275,250,225,200,175,150,125,100,90,80,75,70,65,60,55,50,45,40,35,30,25,20,15,10 or 5 meV than the band gap of fixed (III) family metal nitride.

The film resiativity of the gallium nitride film that obtains can be 10 ⁴-0.0001,10 ³-0.0001,10 ²-0.0001,10-0.0001,1-0.0001,0.1-0.0001,10 ⁴-0.001,10 ³-0.001,10 ²-0.001,10 ¹-0.001,1-0.001,0.1-0.001,0.01-0.001,0.05-0.001,10 ⁴-0.002,10 ³-0.002,10 ²-0.002,10 ¹-0.002, between 1-0.002,0.1-0.002,0.01-0.002 or the 0.05-0.002 ohm.cm.

The oxygen concn that the gallium nitride film that obtains shows can be lower than 1.6,1.5,1.4,1.3,1.2,1.1,1.0,0.9,0.8,0.7,0.6,0.5,0.4,0.3,0.2,0.1,0.075,0.05 or 0.038 atom %.

In the inventive method each all can be implemented in the situation that does not have ammonia.This method can be implemented in the situation that does not have hydrogen, the hydrogen in may being included in (III) family metal species.Hydrogen and ammonia cannot be added in the growth room.In each of the invention described above method, nitrogen precursor is the active neutral nitrogen kind from nitrogen plasma.In each of the invention described above method, nitrogen precursor is the active neutral nitrogen kind of the nitrogen plasma that produces from microwave.In each of the invention described above method, between nitrogen plasma that microwave produces and substrate, can use baffle plate or impeller.Nitrogen precursor cannot be from hydrogeneous nitrogen kind.Nitrogen precursor cannot from, for example, the nitrogen kind of ammonia, hydrazine, alkyl hydrazine (for example, dimethylhydrazine, diethyl hydrazine, methylethyl hydrazine) or its mixture.By the film of method Grown GaN of the present invention and InN and composition thereof and the ternary film of Ga, In and Al can be semiconductive, and does not need other annealing steps.

The device of growing metal nitride film

According to second aspect, the invention provides the device of strengthening chemical vapour deposition growth regulation (III) family metal nitride film by remote plasma, this device comprises:

(a) growth room;

(b) be selected from substrate and the target that comprises the substrate of buffer layer, this target is positioned at the growth room;

(c) well heater, its be used for target be heated to about 400 ℃ to about 750 ℃ temperature range, this well heater is positioned at the growth room;

(d) vacuum system, it is used for discharging the gas of growth room;

(e) sealed tube (containment tube), it is made by quartz, silicon-dioxide or boron nitride, and is communicated with growth room's fluid, and the sealing pipe is used for the active neutral nitrogen kind stream that the nitrogen plasma away from the growth room produces is delivered in the growth room;

(f) be used in the growth room forming the device of reaction mixture, this reaction mixture comprises (III) family metal species that can form (III) family metal nitride film with nitrogen kind reaction, thus film is applicable to form under the condition of device purposes be positioned at add the film of (III) family metal nitride on the thermal target.

This device may further include: be used for operating process with the pressure-controlling in the growth room at the device of about 0.1 Torr to the scope of about 10 Torr, thereby make film be applicable to the device purposes.

This device may further include: be used for preventing substantially that in (III) family metal nitride film process of growth the average energy that produces from arriving the device of substrate more than or equal to the active neutral nitrogen kind of the bond energy of (III) family metal nitride key in nitrogen plasma, thereby make film be applicable to the device purposes.

This device may further include: be used for the indoor oxygen partial pressure of control growing so that film shows the device of the oxygen concn that is lower than about 1.6 atom %, thereby make film be applicable to the device purposes.

This device may further include: be used for the device of nitrogen gas generation nitrogen plasma that is less than or equals the impurity of 10 parts/1,000,000,000 parts of nitrogen from comprising, thereby make film be applicable to the device purposes.

Well heater can be a resistance heater, and it comprises:

Resistance substrate with upper surface, this substrate are made by the material that is selected from following material or are comprised the material that is selected from following material: the nitride of boron, silicon or aluminium or the compressing grains of carbide or its combination; And

Be positioned at upper surface of base plate or coupled heating unit, it comprises the conductive component with selected resistance, produces heat when the heating unit with convenient electric current, and wherein these parts are made by carbon fiber or comprised carbon fiber.

According to an embodiment of the invention, the device of a kind of growth regulation (III) family metal nitride film is provided, this device comprises:

-growth room;

-be selected from substrate and the target that comprises the substrate of buffer layer, in use this target is positioned at inside, growth room, and the crystalline structure of substrate or buffer layer is fit to growing metal nitride film thereon;

-vacuum system is used for discharging the gas of growth room;

-sealed tube, it is made by quartz, silicon-dioxide or boron nitride, and is communicated with growth room's fluid, and the sealing pipe is used for active neutral nitrogen kind stream is delivered in the growth room;

-be used for providing the device of metal nitride steam at target proximity, so that on target, form the solid metal nitride film in the device operating process; And

-be used to make film to be applicable to the device of device purposes.

This device may further include the sample transfer chamber, and it took in substrate at substrate before the growth indoor positioning.

This device can comprise in addition and is applicable to that it is transferred to the growth room with sample from the sample transfer chamber subsequently by preparing sample from transferring chamber's exhausted air with the isolated preliminary vacuum lock of sample transfer chamber and surrounding environment (load lock).

According to an embodiment of the invention, the device of a kind of growth regulation (III) family metal nitride film is provided, it comprises:

-growth room;

-be selected from substrate and the target that comprises the substrate of buffer layer, in use this target can be positioned at the growth room, and the crystalline structure of substrate or buffer layer is fit to growing metal nitride film thereon;

-vacuum system, it is used for discharging the gas of growth room;

-be used for operating process with the pressure-controlling in the growth room at the device of about 0.1 Torr to the scope of about 10 Torr, thereby make film be applicable to the device purposes.

The device that is used for the indoor pressure of control growing can be the valve that is communicated with the growth room, and described valve links to each other with vacuum pump.

According to another implementation of the invention, provide the device of a kind of growth regulation (III) family metal nitride film, it comprises:

-growth room;

-vacuum system is used for discharging the gas of growth room;

-be used for preventing substantially that in (III) family metal nitride film process of growth the average energy that produces from arriving the device of substrate more than or equal to the active neutral nitrogen kind of the bond energy of (III) family metal nitride key in nitrogen plasma, thus make film be applicable to the device purposes.

When (III) family metal nitride film was gan, the active neutral nitrogen kind that average energy is less than or equal to about 2.2 eV can arrive target.

When (III) family metal nitride film was aluminium nitride, the active neutral nitrogen kind that average energy is less than or equal to about 2.88 eV can arrive target.

When (III) family metal nitride film was indium nitride, the active neutral nitrogen kind that average energy is less than or equal to about 1.93 eV can arrive target.

Be used for preventing substantially that the average energy that produces at nitrogen plasma from arriving the device of target more than or equal to the active neutral nitrogen kind of the bond energy of (III) family metal nitride key, can comprise at least one impeller or at least one baffle plate or its combination.Baffle plate or impeller can and be used between the source of long-range generation nitrogen plasma in target.Impeller can apply centrifugal force to active neutral nitrogen kind.Impeller can prevent to migrate on the target along straight line or " hair-line(crack) " from the active neutral nitrogen kind that nitrogen plasma emits substantially.

In yet another embodiment of the present invention, provide the device of a kind of growth regulation (III) family metal nitride film, it comprises:

-growth room;

-vacuum system, it is used for the exhaust from the growth room;

-be used for substrate is heated to the device of the temperature between 400 ℃ and 750 ℃, thus make film be applicable to the device purposes.

The device that is used for heated substrate can be the well heater according to seventh aspect present invention.

-growth room;

-vacuum system, it is used for the exhaust from the growth room;

-be used for the indoor oxygen partial pressure of control growing so that make film show the device of the oxygen concn that is lower than about 1.6 atom %, thus make film be applicable to the device purposes.

The device that is used for the indoor oxygen partial pressure of control growing can comprise that at least a portion with the sealed tube internal surface contacts with nitrogen plasma, wherein this contact procedure is implemented about 1 hour to 100 hours time at about 10 mTorr to the pressure of about 100 Torr, this contact procedure makes at least a portion silicon-dioxide in the sealed tube and the nitrogen ionic reaction in the nitrogen plasma, thereby makes at least a portion silicon-dioxide change the chemical species that do not discharge Sauerstoffatom or discharge less Sauerstoffatom at about 10 mTorr into to the pressure of about 100 Torr.Oxygen partial pressure can be less than 10 ^-2, 10 ^-3, 10 ^-4, 10 ^-5, 10 ^-6, 10 ^-7, 10 ^-8, 10 ^-9, 10 ^-10, 10 ^-11Or 10 ^-12Torr.

In another embodiment of the present invention, the device of a kind of growth regulation (III) family metal nitride film is provided, it comprises:

-growth room;

-vacuum system, it is used for the exhaust from the growth room;

-be used for the device of nitrogen gas generation nitrogen plasma that is less than or equals the impurity of 10 parts/1,000,000,000 parts of nitrogen from comprising, thus make film be applicable to the device purposes.

Be used for from comprising that the device of nitrogen gas generation nitrogen plasma that is less than or equals the impurity of 10 parts/1,000,000,000 parts of nitrogen can comprise, for example, purify the nitrogen that is used to produce plasma body with gas purifier such as metal zeolite cleaner (for example, the Ni-based zeolite cleaner of silicic acid).

-growth room;

-vacuum system, it is used for the exhaust from the growth room;

-wherein sealed tube is in the following manner with respect to substrate orientation: in the operation of equipment process, active neutral nitrogen kind is directly led to the central zone of substrate along passage, the position of this passage becomes the angle of 50 degree to the right angle basically with the plane that comprises substrate, thereby makes film be applicable to the device purposes.

The direction of passage can meet at right angles substantially with the plane that comprises substrate.

-growth room;

-vacuum system, it is used for the exhaust from the growth room;

Wherein be used for positioning with respect to substrate in the following manner near the device that metal nitride steam is provided the substrate: in the operation of equipment process in the device operating process, metal nitride steam directly leads to the central zone of substrate along passage, the position of this passage becomes the angle of 45 degree to the right angle substantially with the plane that comprises substrate, thereby makes film be applicable to the device purposes.

The planar direction can meet at right angles with the plane that comprises substrate.

RPECVD is thought a kind of low damage growing technology widely, yet the inventor has observed the film that uses the growth of RPECVD method and can have been damaged by elasticity and the active neutral nitrogen kind of high energy that the plasma body that is produced by microwave forms.This impel the inventor considered many prevent these species arrive films, still allow simultaneously the low species of average energy can with the mode of the trimethyl-gallium that is used to form metal nitride (or trimethyl indium or trimethyl aluminium) reaction.

Microwave and RF plasma source are used for molecular beam epitaxy (MBE) growth of nitride-based semiconductor.They have used the outlet opening with duck eye to keep high pressure in plasma side, and the active specy bundle is directed into the low relatively chamber of working pressure (～10 simultaneously ^-5Torr) in.Be used for around the active specy that the MBE system grows often is directed into baffle plate, the gate (shutter) that its path is limited in use in these MBE systems on every side.Also can use the opening that uses for small area MBE source active neutral nitrogen kind to be directed to the great area that is used for the film growth.Whether yet MBE has used much lower pressure, no matter use baffle plate and gate, this pressure all can cause the damage of the active neutral nitrogen kind of elasticity and high energy.

Do not expect to RPECVD also should keep similar situation (active neutral nitrogen kind can be directed into be used for film grow area greatly) compare with the MBE that uses particle beam and more approach the fluidised form condition because active specy leaves the condition in plasma body zone.As if the higher growth pressure that uses among the RPECVD can not hinder the active neutral nitrogen kind of the elasticity that forms in microwave plasma to guide again to carry out large area deposition, prevent the damage to film simultaneously substantially.

Be used for preventing substantially that the average energy that produces at nitrogen plasma from can comprise one or more baffle plate and/or impeller so that plasma flow is guided to bigger zone again more than or equal to the device that the active neutral nitrogen kind of the bond energy of (III) family metal nitride key arrives substrate, so that deposit more even metal nitride film.One or more baffle plate or impeller can be used to make plasma body or its one or more compositions to be shifted from the medullary ray of middle section such as conduit, pipeline or flexible pipe radially.Perhaps, the impeller of fan form (comprise and be installed in the plasma channel and sword sheet or the fin angled with it) can be used for preventing substantially producing the active neutral nitrogen kind arrival substrate of average energy more than or equal to the bond energy of (III) family metal nitride key at nitrogen plasma.

Baffle plate or impeller can be used for the growth district of (III) family metal nitride film is increased to bigger area, still use the plasma source of relative small area simultaneously.

The device of the third aspect is to use higher growth pressure with respect to the Inherent advantage of MBE system in the growth room, this has limited the film in the thin film growth process and has damaged.

The method according to this invention and device have greatly improved quality and the homogeneity by RPECVD method Grown GaN.

Higher uniformity of film can make the depositional area of GaN greater than the conventional area that can reach.

Improved growth conditions in the method according to this invention has allowed successfully to have used the ZnO buffer layer, has obtained the GaN film of good quality.

Formation can make film grow on diameter is about 4 inches surf zone according to the baffle plate of the part of growing system of the present invention or impeller, and this area is far longer than thinks the area that the small area microwave plasma source might reach before the people.

Might provide lattice match and hot matching layer further to carry out epitaxial growth of high quality GaN by the method according to this invention Grown GaN film, this high-quality GaN has low-dislocation-density on different heterojunction structure devices.

Deposition method according to the present invention is based on traditional MOCVD growth, but allows metal nitride in about 400-650 ℃ lesser temps deposition.Excimer laser away from substrate support can be used to increase gas molecule dissociating to free radical.

The metal nitride growth of low temperature (III) family, for example GaN growth has certain advantage of putting into practice.These advantages comprise the possibility of device that use cost is lower and substrate, use buffer layer (for example ZnO, SiC, HfN, GaN, AlGaN etc.), lower foreign matter content, when the growth thin layer significantly the interface and between GaN film and substrate lower thermal stresses.Its main shortcoming be between film and the substrate sticking power a little less than, and hydrogen, oxygen and the carbon that in process of growth, might mix higher degree.

Passivation

According to a third aspect of the invention we, provide a kind of processing to make or comprise the method for the target of quartz or silicon-dioxide by quartz or silicon-dioxide, this method comprises the steps:

-at least a portion of target surface is contacted about 1 hour to about 100 hours time at about 10 mTorr with nitrogen plasma to the pressure of about 100 Torr; With

-make at least a portion silicon-dioxide in the target surface and the nitrogen ionic reaction in the nitrogen plasma, do not discharge Sauerstoffatom or discharge the seldom species of Sauerstoffatom thereby at least a portion in these silicon-dioxide is changed under described pressure.

With regard to the third aspect, this target can be any target that can discharge Sauerstoffatom that comprises.

Contact procedure is preferably carried out under the pressure near the lower limit of aforementioned pressure scope.

Restoring under described pressure for fear of species is the species that discharge Sauerstoffatom or discharge more Sauerstoffatom, and this target optimum selecting remains on aforementioned about 10 mTorr to the pressure of about 100 Torr in nitrogen stream, or is being lower than 10 ^-6In the vacuum of Torr, and avoid ingress of air, water vapour or contain other any material or gas of aerobic.Therefore, the method for this aspect can be included in after target surface partly changes described species into according to the present invention, prevents the step that target surface contacts with air, water vapour or oxygen containing material or gas.

Silicon-dioxide can be transformed into the nitride species.

Target can be seal protection container or sealed tube.Sealed vessel or sealed tube go in the above-mentioned RPECVD method, so as before the step of growing metal nitride film or among will comprise electric neutrality but the nitrogen plasma of chemically active species is introduced in the growth room.This metal can be a gallium.

According to a forth aspect of the invention, provide a kind of method of growing metal nitride film, this metal is selected from gallium, aluminium, indium and combination thereof, and this method comprises the steps:

-will make or comprise that at least a portion of the plasma body sealed tube internal surface of quartz or silicon-dioxide contacts with nitrogen plasma by quartz or silicon-dioxide, wherein this contact procedure was carried out about 1 hour to about 100 hours to the pressure of about 100 Torr at about 10 mTorr; Then,

-in the growth room, provide on the suitable substrate, the film of deposition solid metal nitride from metal nitride steam, will comprise electric neutrality simultaneously but the nitrogen plasma of chemically active species by in this pipe importing growth room.

Contact procedure is preferably carried out under near the pressure of aforementioned pressure scope lower limit.Time can be about 5,7,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,27,30,33,36,40,45,50,55,60,65,70,75,80,85,90,95,100 hours or more.

For avoiding species to restore under described pressure for discharging Sauerstoffatom or discharging the more species of polyoxy atom than described species, this target optimum selecting remains on aforementioned about 10 mTorr to the pressure of about 100 Torr in nitrogen stream, or is being lower than 10 ^-6In the vacuum of Torr, avoid ingress of air, water vapour simultaneously or contain other any material or gas of aerobic.

Contact procedure can be carried out to about 1000 ℃ temperature at about 100 ℃.

In contact procedure, when nitrogen plasma is present in this pipe and supplies electric neutrality but during chemically active species, at least a portion of the silicon-dioxide that exists in this tube-surface can change the species that do not discharge Sauerstoffatom or discharge less Sauerstoffatom in the growth room by this pipe.The species that silicon-dioxide was transformed into can be nitride-based species.

By metallorganics steam such as trimethyl-gallium and ammonia stream is reacted, can form metal nitride film in the presence of nitrogen plasma.This metal can be a gallium.

Method according to fourth aspect present invention can comprise the step that repeats contact procedure and/or deposition step, the oxygen that exists in the solid metal nitride film is reduced to the level of needs, and this level can be measured by the ratio of Sauerstoffatom and nitrogen-atoms in the solid metal nitride film.At metal nitride is in the situation of gan, and the level that needs can be that the degree of depth place that surpasses about 300nm on distance gallium nitride film surface is lower than about 0.1.

Can be included on the substrate before the metal refining nitride film according to the method for fourth aspect present invention, make substrate stand the step of vacuum.If there is nitrogen stream, very aerial pressure can be about 10 mTorr to about 100 Torr, perhaps do not exist any quilt deliberately to introduce in the situation of gas of growth room, this pressure can be less than 106 Torr.

Substrate can stand vacuum in the growth room or in separate chambers (it can be the form of feed compartment or preliminary vacuum lock).May further include after substrate as above stands vacuum according to the method for fourth aspect present invention it is transferred to life from separate chambers, feed compartment or preliminary vacuum lock. the step of long chamber.This method may further include prevent substrate after standing vacuum with take the step that the oxygen species contact.

And this method can be included on the substrate and to be heated before the growing metal nitride film or in other mode it to be carried out pretreated step.

According to a fifth aspect of the invention, providing a kind of handles or makes the device of its passivation, this device to comprise to be used at nitrogen plasma with this surface or should provide the contact device that contacts between the part of surface at least a portion of being made by quartz or silicon-dioxide or comprise the target surface of quartz or silicon-dioxide.

This device may further include the vacuum system that is used for providing vacuum in the presence of at least a portion of this target surface.When this device uses and Dang Qi when not using, vacuum system provides vacuum in the time of can being used for existing on this surface.

Nitrogen plasma can comprise electric neutrality but chemically active species.

This device can comprise the plasma generator that can produce nitrogen plasma.

This device may further include the growth room that is communicated with sealed vessel or sealed tube, so that in the operating process of RPECVD method, and gallium nitride film growth on suitable substrate.

This device can be operated to the pressure of about 100 Torr at about 10 mTorr.Perhaps, or in addition, this device can be used for moving about 0.5 minute to about 100 hours in about 500 ℃ to 1000 ℃ temperature.Oxygen partial pressure in this device can be less than 10 ^-2, 10 ^-3, 10 ^-4, 10 ^-5, 10 ^-6, 10 ^-7, 10 ^-8, 10 ^-9, 10 ^-10, 10 ^-11Or 10 ^-12Torr.Oxygen partial pressure in this device can be 10 ^-3-10 ^-12Torr, 10 ^-3-10 ^-11Torr, 10 ^-3-10 ^-9Torr, 10 ^-4-10 ^-9Torr, 10 ^-5-10 ^-9Torr, 10 ^-6-10 ^-9Torr, 10 ^-6-10 ^-12Torr, 10 ^-7-10 ^-12Torr, 10 ^-6-10 ^-11Torr, 10 ^-7-10 ^-11Torr, 5 * 10 ^-7-10 ^-10Torr, 10 ^-7-10 ^-9Torr, 10 ^-3-10 ^-8Torr, 10 ^-3-10 ^-8Torr, 10 ^-5-10 ^-8Torr, 10 ^-6-10 ^-8Torr, 10 ^-7-10 ^-8Torr, 10 ^-3-10 ^-7Torr, 10 ^-4-10 ^-7Torr, 10 ^-5-10 ^-7Torr, 10 ^-6-10 ^-7Torr, 10 ^-2-10 ^-9Torr, 10 ^-3-10 ^-9Torr, 10 ^-4-10 ^-9Torr, 10 ^-5-10 ^-9Torr, 10 ^-6-10 ^-9Torr, 10 ^-7-10 ^-9Torr, 10 ^-2-10 ^-10Torr, 10 ^-3-10 ^-10Torr, 10 ^-4-10 ^-10Torr, 10 ^-5-10 ^-10Torr, 10 ^-6-10 ^-10Torr or 10 ^-7-10 ^-10Between the Torr.

This device may further include the sample transfer chamber that is used for taking in before growth on the suitable substrate at gan this suitable substrate.

Perhaps, or in addition, this device can comprise the preliminary vacuum lock, and it is used for sample transfer chamber and surrounding environment are separated, and be used for by from transferring chamber's exhausted air with the preparation sample, subsequently sample is transferred to the growth room from the sample transfer chamber.

According to a sixth aspect of the invention, provide a kind of device of growing metal nitride film, this metal is selected from gallium, aluminium, indium and combination thereof, and this device comprises:

-growth room;

-in use being positioned at the substrate of growth room, the crystalline structure of this substrate is fit to growing metal nitride film thereon;

-vacuum system, it is used for the exhaust from the growth room;

-by sealed vessel or sealed tube that quartz or silicon-dioxide are made, it is communicated with growth room's fluid, and sealing container or sealed tube are used for active neutral nitrogen kind stream is directed in the growth room; With

-be used near substrate, providing the device of metal nitride steam in the device operating process, so that the solid metal nitride film is deposited on the substrate,

Wherein at least a portion of sealed vessel or sealed tube internal surface has changed passivation species into, and this passivation species in use can not discharge Sauerstoffatom or discharge less Sauerstoffatom.

Nitrogen plasma can comprise electric neutrality but chemically active species.Electric neutrality but chemically active species can be nitrogen-atoms.

Can be to the transformation of passivation species by a part of and nitrogen plasma extremely contact about 1 hour to 100 hours under the pressure of about 100 Torr at about 10 mTorr and carry out with the surface of sealed vessel or sealed tube or its.

Passivation species can be nitride-based species.

Be used in the growth room, providing the device of gan steam can comprise that the permission trimethyl-gallium flows to the pipe into growth room, substrate upstream; And, in some embodiments, can be included in the device operating process allow ammonia to flow to into the growth room in case with the trimethyl-gallium reaction, thereby form the pipe of gan steam.

Pressure when sealed vessel or sealed tube contact with nitrogen plasma can be approximately between 10mTorr and about 10 Torr, perhaps between about 1 Torr and about 10 Torr.Pressure preferably is lower than 10 Torr, and suitable is that about 1 Torr is to about 5 Torr.

Device according to sixth aspect present invention may further include vacuum system, and it is used for providing vacuum when at least a portion of target surface exists.When device when in use and not using, vacuum system provides vacuum in the time of can being used for existing on the surface.

May further include feed compartment or preliminary vacuum lock according to the device of sixth aspect present invention, they can be used for before substrate is transferred into the growth room adjusted.Feed compartment or preliminary vacuum lock is pumped into vacuum before can be in substrate is transferred to the growth room.This device can comprise locks the transfer device that shifts in the growth room with substrate from feed compartment or preliminary vacuum.Transfer device can be a pair of pliers, transport unit, flashboard (shutter) or the suitable carrier or the form of lifting or lowering means.

Can on the surface of sealed vessel or sealed tube, implement to about 1200 ℃ temperature at about 100 ℃ according to the method for third aspect present invention.Temperature can be from about 100 ℃ to about 900 ℃, perhaps from about 100 ℃ to about 800 ℃, perhaps from about 100 ℃ to 700 ℃.

In preferred implementation of the present invention, the lip-deep temperature of sealed vessel or sealed tube is about 200 ℃ to about 600 ℃.The temperature of quartzy sealed vessel or sealed tube generally is elevated to about 200 ℃ in operating process, but when silicon-dioxide or the quartzy impurity that contains maybe when the heat that is passed to pipe from plasma body greatly the time, it may be elevated to the interior comparatively high temps of aforementioned temperature scope.

The temperature that the should be appreciated that plasma body generally aforementioned temperature than pipe or sealed vessel is higher.

And, be to be understood that, sealed vessel or sealed tube contact up to its surface with for some time of the abundant chemical passivation of nitrogen with plasma body at first through associating, the surface temperature of sealed vessel or sealed tube may raise, and may booster action be arranged from plasma body to this process to the heat passage of sealed vessel or sealed tube.

Nitrogen can have high purity.For guarantee that the gallium nitride film of growing contains the least possible impurity and has the least possible defective in device according to the present invention, the nitrogen that is used for nitrogen plasma preferably has high purity.It preferably contains and is less than 10 parts/1,000,000,000 parts total impurities, more preferably less than about 5 parts/1,000,000,000 parts total impurities, further preferably is less than 1 part/1,000,000,000 parts total impurities.Therefore, any moisture, oxygen, carbonic acid gas or any other impurity that may exist all preferably were removed before nitrogen is transformed into plasma body.

For preventing reoxidizing of sealed vessel or sealed tube surface,, and preferably when not using, keep in a vacuum preferably with itself and air insulated.

The external diameter of the standard-size tube through being commonly used to hold nitrogen plasma is about 1 inch (approximately 25mm).The shortcoming that caliber is big is that it may allow microwave by entering in the growth room, considers its disadvantageous effect to gallium nitride film, and this is undesirable.But, existing when still containing the magnetic field of microwave, can use bigger pipe, and when use substitutes microwave than low radio frequency or DC electromagnetism excitation, also can use bigger pipe.

Nitrogen plasma can use magnetron to form by using microwave.The rated output of magnetron can reach about 500 watts.

The power of magnetron can be about 450 to about 700 watts, if the power of magnetron is higher than about 700 watts, tend to make the temperature of sealed tube or sealed vessel to raise, this is not hoped, because it may cause oxygen project (oxygen items) to increase from drive out of (dislodgement) of sealed tube or vessel surface.

Stable for guaranteeing nitrogen plasma, the power of magnetron is enhanced following level: in this horizontal plasma body pinkiness.In some cases, plasma body also can be orange.

Plasma body can produce by using suitable electromagnetic radiation bandwidth.Therefore, the frequency frequency of electromagnetic radiation can about 0.1 hertz to the scope of about 10 mega hertzs.

The frequency holder of microwave is selected in about 2 mega hertzs to the scope of about 3 mega hertzs.

In the situation of the electromagnetic radiation that needs different frequency, radio frequency (about 13.56 megahertzes) or use the situation of DC plasma generator (0 megahertz) for example, frequency can be lower.

It is desirable to, before passivation, all water vapour are removed from device with avoid after whenever water vapour enters in the system with other oxygenated species.On believing that water molecules itself can the wall attached to sealed tube or sealed vessel, and the total pressure in the system there is not any effect.By in device according to the present invention, adding the preliminary vacuum lock, even can not avoid the increase of water vapour in the device also it can be reduced to minimum level fully.

Can be according to the oxygen partial pressure in the device of the present invention less than 10 ^-7Torr.Oxygen partial pressure in the device can be less than 10 ^-3, 10 ^-4, 10 ^-5, 10 ^-6, 10 ^-7, 10 ^-8, 10 ^-9, 10 ^-10, 10 ^-11Or 10 ^-12Torr.Oxygen partial pressure in the device can be 10 ^-3-10 ^-12, 10 ^-3-10 ^-11, 10 ^-3-10 ^-10, 10 ^-4-10 ^-10, 10 ^-5-10 ^-10, 10 ^-6-10 ^-10, 10 ^-7-10 ^-10, 10 ^-8-10 ^-10Perhaps 10 ^-9-10 ^-10In the scope of Torr.

Preferably under the pressure approximately identical, carry out according to passivating method of the present invention with the pressure of gallium nitride film growth.

Perhaps, can use different pressure.

Usually, under low pressure each ion of the nitrogen-atoms that obtains of the plasma body of Chan Shenging has more energy, although ion is less.

Optimum pressure depends on the size of sealed vessel or sealed tube.In general, passivation pressure is high more, the time of the surface contact nitrogen plasma of sealed vessel or sealed tube just can be short more, and passivation pressure is low more, and needing to implement Passivation Treatment then needs long more so that obtain the time of satisfied nitrogenization on the surface of sealed vessel or sealed tube.

Determine that optimum pressure will consider the intensity and the characteristic of the size of sealed tube or container, microwave energy and employed material.Optimum pressure depends on also how system optimizes.Residual gas analysis instrument or plasma emission spectroscopy can be used to measure the quality of the nitrogen that is used to produce plasma body.

Have been found that, when growing according to the method for second aspect present invention, on by silicon-dioxide quartz (silica quartz) sealed vessel of making or the surface of sealed tube (its method according to this invention carry out passivation), can access gallium nitride film, the oxygen concn of this film is less than 10 ¹⁹Individual atom/cm ³

If the surface of quartzy sealed vessel of new silicon-dioxide or sealed tube is not passivated, use this sealed vessel or sealed tube can be several percentage points by the oxygen concn in the gallium nitride film of RPECVD method growth.

For making LED, oxygen concn is 10 ²⁰Gallium nitride film be acceptable.But for laser diode, oxygen concn need be less than 10 ¹⁸Individual atom/cc.

Oxygen concn in the gallium nitride film is low more, and its electric conductivity is low more.

It is desirable to, growth has the gallium nitride film of low electric conductivity.Oxygen is not the doping agent of the good quality of gan, but because its cancellation light emission.The preferred silicon that uses is as doping agent.

For making LED, can use high-caliber silicon-doped gallium nitride film.Use for these, must have low-down oxygen concn.

It is desirable to, obtain the low-down gallium nitride film of doped level and residual carrier has very high mobility.

It is desirable to, it is about 50 that the electronic mobility in the gallium nitride film is higher than, preferably about 50 to about 1200 scope.

The ion that produces in the RF plasma body often has much higher energy than the ion that produces in microwave plasma, and quartz is penetrated more.

Microwave provides the electric field of the electronics that can remove the nitrogen purge gas molecule.What produce plasma body is the electric field of electromagnetic radiation.

If nitrogen plasma glimmers, then power is too low and should improve power.If color remains bright pink colour (bright pink), then power is in gratifying level.The higher-energy conversion taken place in orange showing in nitrogen plasma, so plasma body is a high energy more.

Distance between plasma body and the substrate should be enough to prevent that the ion from plasma body from arriving gallium nitride film, because they are high energy and damage that can cause film.

Impurity in silicon-dioxide or quartz is many more, and when nitrogen plasma produced in pipe or container, its temperature tended to high more.

Metal zeolite cleaner can be used to purify the nitrogen that is used to produce plasma body.

For preparing vacuum system, can at first reach higher temperature, remain on vacuum by the operating pressure that air is pumped in pressure is reduced to the aforementioned pressure scope simultaneously from device.

Gallium nitride film uses the RPECVD method to grow under about 650 ℃ temperature.In traditional MOCVD method, growth temperature is about 1000 ℃.

Comprise in the scope of the present invention and use RF plasma body and DC plasma body.

Comprise also in the scope of the present invention that frequency of utilization is the microwave of about 2.45 GHz, it is not included in the magnetic field.In this case, the diameter of sealed tube can be in the magnitude of about 0.5cm to about 2-3cm.If must prevent that microwave transmission from advancing growth district, what for extremely may be less than the diameter of 0.5cm.For higher microwave frequency, need less caliber to prevent that microwave transmission from entering in the growth room, and, can use bigger caliber for lower microwave frequency.

Or, can use RF helical source (Helicon source).This provenance can use the plumber of 30cm diameter to do.If the use magnetic confinement, for example in the situation of using ECR (electron cyclotron resonace) plasma source, microwave also can use the plumber of this diameter to do, because microwave power can more effectively be absorbed by plasma body in the magnetic confinement zone.

Suitably note the homogeneity of constraint and plasma body, can use up to about 60cm than major diameter.

In the RPECVD method, use higher vacuum condition, and because sealed vessel or sealed tube that the preliminary vacuum lock is caused seldom contact with air, therefore sample substrate is placed in the independent container before being imported into into main growth room (it is ingress of air not), and the main chemical reactions that takes place at fused quartz or quartz surfaces is considered to:

SiO _{2 (solids)}+ N _{2 (plasma bodys)}---Si _xN _{Y (solid)}+ N ₂O _(gas)(2)

It is also believed that, when reaction is carried out, Si _xN _ySpecies accumulate on the surface of sealed vessel or sealed tube, like this, and SiO seldom ₂Can be used to produce nitrous oxide, therefore oxygen amount minimizing that discharges from the surface and container or pipe are passivated.

Advantage of the present invention is, the quartz (or fused quartz) that is used to hold plasma body is " passivation ", that is, it is become chemically inert, and the oxygen species can not discharge from quartzy (silicon-dioxide) wall with the level that influences film quality in the process of growth of gallium nitride film like this.Deactivation method can be as the part of the method described in first aspect and the embodiment thereof.

The nitride-based surface of tube wall have been found that among initial treatment step process even afterwards, the concentration of the oxygen amount that discharges from pipe reduces gradually, because may be passivated.Passivating process can spend 0.75 to 5 day or the longer time, 0.8 to 3 day or 1 to 2 day.Passivating process can spend 0.75,0.8,0.9,1,1.1,1.2,1.3,1.4,1.5,1.6,1.7,1.8,1.9,2,2.25,2.5,2.75,3,4.25,4.5,4.75,5,6,7,8,9,10 or more days.

And, also have been found that, do not contact if will guarantee to be held under ultrahigh vacuum(HHV) (UHV) condition with air or hydrogenous plasma body, if and system is repeatedly never leaving unused for a long time between the film growth, passivation still is kept perfectly and is can be used in the film growth of unlimited number of times after this, because the use meeting of nitrogen plasma is with its reinforcement in each thin film growth process.

If for some reason, this device was had in the time in several weeks of repeatedly leaving unused between the film growth, the then nitrogen plasma of short period of time passivation again (may continue 1 to 3 hour, this depends on the residual impurity in the vacuum system) is necessary for the oxygen evolution that reduces tube wall once more.But, if contact with air at any stage pipe, (hydrogen class plasma body will cause the erosion of pipe perhaps to contain ammonia or other species relevant with hydrogen at plasma body, this can remove passivation layer) situation in, then Passivation Treatment will spend 0.75 to 5 day or the longer time once more again, 0.8 to 3 day or 1 to 2 day.Passivation Treatment may spend 0.75,0.8,0.9,1,1.1,1.2,1.3,1.4,1.5,1.6,1.7,1.8,1.9,2,2.25,2.5,2.75,3,4.25,4.5,4.75,5,6,7,8,9,10 or more days again.

Usually in older UHV environment, water vapour is that main remnants take the oxygen species, and believes in growing system and can cause Si with contacting of residual water vapor _xN _yThe slow degraded of passivation layer, thus the hydrolysis of nitride layer and the formation of silicon hydroxide and oxide species caused.Therefore, if system is idle for a long time, for example surpassed for 2 weeks, required time when then time of needing of passivation will substantially exceed continuous the use again is because this oxyhydroxide or oxide skin gathering on pipe internal surface will be increased.

The residual water vapor that has higher amount in older HV system, the reaction scheme that equation 2 provides can't realize because in the nitridation process of pipe, the competing reaction of pipe hydrolysis guaranteed oxygen constantly restock to the surface of pipe.Opening once again continuously of system also is exposed to pipe (even having the nitrogen gas stream from system to exist) in the high-caliber water vapour in open process, compare with new UHV system, the continuous opening once again of system can guarantee background water vapour level by restock to much higher minimum level.

For using passivation pipe Grown GaN sample at 650 ℃ by REPCVD, secondary ion mass spectrometry (SIMS) (SIMS) result shows, it is low to be on close level for UHV system oxygen, is very low with comparing at about 1000 ℃ of films of growing down by the metal organic-matter chemical vapour deposition.

Allow RPECVD film growth method is used for the growth of nitride film and can not have a remarkable oxygen contamination according to device according to the present invention from quartzy (silicon-dioxide) plasma body sealed tube.

The method according to this invention also provides following advantages: promptly, gallium nitride film can use RPECVD film growth method growth, this means that film can grow under obviously lower temperature.

The further advantage of the method according to this invention is, can use nitrogen rather than ammonia as plasma source, and this just means the hydrogen contamination that can be avoided deriving from ammonia.

The GaN of good quality will reduce the cost of GaN LED class interior lighting in the growth of lesser temps.

Therefore, the present invention has obtained obvious improvement aspect following: the present invention uses the RPECVD method to produce the GaN film, still can reach the equal in quality of the film that mocvd method can reach simultaneously.

It should be noted that when mentioning active neutral nitrogen kind in nitrogen plasma moves to the growth room, term " conveying " is appreciated that to have identical implication with " transfer ".

Heater assembly

According to a seventh aspect of the invention, provide a kind of resistance heater, it comprises:

-having a resistance substrate of upper surface, this substrate is made by the material that is selected from following material or is comprised the material that is selected from following material: the nitride of boron, silicon or aluminium or the compressing grains of carbide or its combination; With

-being positioned at upper surface of base plate or coupled heating unit, it comprises the conductive component with selected resistance, produces heat when this heating unit with convenient electric current, wherein these parts are made by carbon fiber or are comprised carbon fiber.

This material also can comprise refractory composite, and it can comprise other material such as boron oxide or TiB2.

As used herein, phrase " is positioned at the upper surface of substrate or coupled " and is appreciated that and comprises following embodiment: wherein this heating unit is positioned on the surface, is positioned among the groove that has on the surface, is embedded among the surface or is positioned at subsurface passage.

Although can work at a lower temperature according to resistance heater of the present invention, the scope of this lesser temps is any temperature on the envrionment temperature, it is particularly suitable for using at high temperature under the aggressiveness working conditions, as those conditions that run in MBE and RPECVD method.For needing pyritous to use in using at these and other, this well heater can about 1000 ℃ to about 1600 ℃ temperature or about 1000 ℃ to about 1500 ℃ temperature work producing heat, 1200 ℃ of preferably approximatelies are to about 1500 ℃ temperature.

Substrate

Substrate can be easily by the compressing grains moulding of boron nitride or aluminium nitride, it can be among compression process or sintering is together afterwards.In its situation about being made by the compression boron nitride, boron nitride can be selected from hexagonal boron nitride, cubic boron nitride, wurtzite BN and rhombus boron nitride.Boron nitride tends to become red-hot shape at about 1300 ℃ to about 1400 ℃ working temperature.

Substrate is preferably by machinable, compression and agglomerating boron nitride or aluminium nitride material grain forming.In order to use the processing of conventional metals cutting technique and steel plant equipment, these material requires have suitable physical strength, oilness, elasticity, modulus, hardness and other characteristic.In practice, machinable pottery, but the form processing of boron nitride for example are very soft with metallographic phase is compared to lathe, because they can be broken into powder under the lathe cutting edge.Pyrolitic boron nitride is very hard frangible, is difficult for being fractured into powder type, therefore often needs to use the device that has the diamond cutting edge to come it is processed.

Under the hot pressing state, hexagonal boron nitride (h-BN) is processing easily, therefore can be shaped to the substrate that has mixture from the hot pressing billet.

Suppose to prevent surface oxidation that h-BN can not drenched by most of molten metals, glass and salt, so it has height endurability to chemical erosion.It also has high dielectric breakdown strength, high volume specific resistance and good unreactiveness.

Being compared as follows of the typical characteristics of hexagonal boron nitride and cubic boron nitride:

Table 1

Characteristic	h-BN	C-BN
Characteristic	h-BN	C-BN	Density (g.cm ^-3)	2.3	2.2
Fusing point (℃)	3000 (decomposition)		Density (g.cm ^-3)	2.3	2.2
Fusing point (℃)	3000 (decomposition)		Hardness (exerting formula hardness 100g) (kg.mm ^-1)	400
The modulus of rupture (MPa)	100(ll?to?press?dir) 50(_to?press?dir)	110	Hardness (exerting formula hardness 100g) (kg.mm ^-1)	400
The modulus of rupture (MPa)	100(ll?to?press?dir) 50(_to?press?dir)	110	Young's modulus (MPa)	20-103
Thermal expansivity Co-eff (RT-1000 ℃ * 10 ^-6)(℃ ^-1)	1(ll?to?press?dir) 4(_to?press?dir)	3.8	Young's modulus (MPa)	20-103
Thermal expansivity Co-eff (RT-1000 ℃ * 10 ^-6)(℃ ^-1)	1(ll?to?press?dir) 4(_to?press?dir)	3.8	Thermal conductivity (W/m. ° of K)	20(ll?to?press?dir) 27(_to?press?dir)
Dielectric breakdown strength (kV.mm ^-1)	35		Thermal conductivity (W/m. ° of K)	20(ll?to?press?dir) 27(_to?press?dir)
Dielectric breakdown strength (kV.mm ^-1)	35		Specific inductivity		4.1
Volume specific resistance	10 ⁸-10 ¹³		Specific inductivity		4.1

The source: Http:// www.azom.com/details.asp? ArticleID=78#Electrical insulatorsAttention: the data of h-BN obtain from hot pressed samples in this table.Because this is a kind of high directivity forming technology, so these characteristics are anisotropic, that is, it is different on all directions relative with pressing direction.Based on this reason, the numerical value of reporting in some numeric ratio characteristic subordinate lists wants high in practice.

Pyrolitic boron nitride has considerably less impurity (＜100 parts/1,000,000 parts) usually, and machinable boron nitride often contains the impurity of much higher level, for example in the percentage magnitude.Its example is, approximately the lime borate of 5wt% to 10wt% (being typically 6wt%) can be used as tackiness agent in a kind of situation, and in another kind of situation, use the boron oxide (referring to, http://www.advceramics.com/geac/products/bn_shapes/ for example) of similar 1wt% to 10wt% (being typically about 5wt%).For the application of not using a large amount of ammonia in the growth room, the purity that is used for the material of substrate can be lower than pyrolysis boron nitride, and condition is that the working temperature of well heater is no more than about 1500 ℃ in process of growth.

As mentioned above, substrate can be selected to be made by aluminium nitride.The thermal conductivity ratio boron nitride height of aluminium nitride, and the heat that can distribute heating unit under working conditions, to produce better.Because its very high thermal conductivity combines with its effective electrical isolation effect, aluminium nitride receives publicity especially.The substrate of making by aluminium nitride can be easily suitable sintering aid is hot-forming to be produced by dry-pressing formed and sintering manufacturing or by using.Surface oxidation takes place about more than 700 ℃ in this material.

Aluminium nitride has extraordinary thermal conductivity.Its thermal expansivity is similar to silicon.It also has good dielectric characteristics and good anti-corrosion.In the atmosphere that it runs in MBE and RPECVD method is stable.

Compare with pyrolitic boron nitride, the hot pressing of nitride and carbide (sintering) particle contains the impurity of higher concentration usually.In the situation of film by molecular beam epitaxy (MBE) growth, the background vacuum is more much lower than the vacuum in the situation of RPECVD growth.Surprisingly, in the RPECVD method, using the hot pressing particle of nitride or carbide is not to be disadvantageous, because its impurity does not have any remarkable effect to the quality of using the metal nitride film of growing according to well heater of the present invention.Be used in the situation of MBE method at well heater according to the present invention, should note only using following material: this material can not cause the pollution of the film of growing under the employed therein in the method relatively low pressure condition.

The hot pressing of nitride or carbide and sintered particles can be by compressing them the suitable powder of the additive that contains rare-earth oxide and so on make.When the powder of nitride or carbide particle during by hot pressing, thaumatropy between its powder and key develop (bonding evolution) make it tight and highly stable so that as scatterer.Compare with pyrolitic boron nitride, the hot pressing particulate material is dirt cheap.

In the situation that substrate is made by machinable hexagonal boron nitride, the thermal conductivity of substrate can be that about 11W/m. ° K is to about 70 W/m. ° K at 25 ℃, preferably approximately 20W/m. ° K is to about 60W/m. ° of K, and more preferably about 30W/m. ° of K is to about 50W/m. ° of K.Higher thermal conductivity in the preferred aforementioned range.

In the situation that substrate is made by machinable cubic boron nitride, the axial thermal conductivity coefficient of substrate can be extremely approximately 150W/m. ° of K of 50W/m. ° of K at 25 ℃, and preferably approximately 100W/m. ° K estimates about 105W/m. ° K.Higher thermal conductivity in the preferred aforementioned range.

In the situation that substrate is made by machinable aluminium nitride, the thermal conductivity of substrate can be extremely approximately 250W/m. ° of K of about 100W/m. ° K at 25 ℃, and preferably approximately 150W/m. ° K estimates about 175W/m. ° K between about 200W/m. ° of K.Higher thermal conductivity in the preferred aforementioned range.

The resistivity of substrate is preferably very high, to prevent that it is with the heating unit short circuit.Therefore, the resistivity of this substrate can be about at least 100 Ω .cm, preferably about at least 1K Ω .cm.

In the situation of using boron nitride, its resistivity can be about 10 ⁸-10 ¹³Ω .cm, as above table 1 is described.

Substrate can be by the following manner manufacturing: at about 1GPa to approximately pressure and about 1300 ℃ to about 1700 ℃ (1400 ℃ to about 1600 ℃ of preferably approximatelies of 100GPa (preferably approximately 7.7 GPa), 1500 ℃ of preferably approximatelies) compacting of temperature or casting boron nitride or aluminium nitride or silicon-carbide particle be so that make the particle sintering, and through being cooled to environmental conditions and forming solid substrate.In this way, can be with independently carbide or nitride particles combine.

Machinable compression boron nitride can obtain from GE-Advanced Ceramics company, Saint-Gobain Ceramics company, International Ceramic Engineering company etc.

Groove

Substrate can have the groove on surface formed thereon, and heating unit can be positioned at wherein.

Groove can be machined into after compression in the upper surface of substrate.Procedure of processing can be a process of lapping.Perhaps, groove can or be used to make the press (for example substrate is therein by hot pressed press) of substrate forming to form by the complementary ridge (complementaryridge) in the proper mold.

Groove can have Any shape.Surpass in the situation of the diameter of upper surface or width in the length of heating unit, heating unit can be shaped as form volution, spiral, ring, round, rectangle, square or be convenient to effectively to the general thereon the substrate of growing film carry out other heat passage Any shape.Groove can be of similar shape with the heating unit of stove.

In one embodiment, groove is configured as and makes two terminal position near the upper surface of base plate center.In another embodiment, the position of notch end is near the periphery of upper surface.In another embodiment of the present invention, notch end is positioned at the opposite end of upper surface.

The length of groove can be chosen as provides the course length that is enough to hold the heating unit with required resistance.Length can according to the size of well heater, make the material of heating unit resistivity, under working temperature, change by the electric current of heating unit, working temperature and other Consideration of needs.Use the Elastic Carbon fiber to be as the advantage of heating unit, groove can be crooked or can be shaped as described above, so that can below the location, and cover the regional or relative of substrate inner face (underside) with this zone, wherein when sample was grown on this substrate top surface, it must heat from the below.Therefore, the length of groove can change in the scope of non-constant width.

On the surface of substrate, can provide groove, and they can be independently or interconnective more than one.Each groove all can hold heating unit, and the ability of these heating unit heated substrate can be identical or different.Heating unit can link to each other with different circuit, and they can be worked independently of each other like this.

The degree of depth of groove can be large enough to hold the integral thickness of heating unit, and perhaps it can be more shallow than the thickness of heating unit.

Heating unit

Heating unit can comprise carbon fiber or carbon fiber bundle.Select as another kind, it can be made by silicon carbide.

Silicon carbide has some Ideal Characteristics, and for example thermal expansivity is low, little, the chemical property of distortion is stable, long service life, easily maintenance etc. is installed.Carborumdum heating element can be used for about 100 ℃ to about 1600 ℃ temperature, typically be used for the comparatively high temps in the aforementioned range, for example about 600 ℃ of temperature to about 1600 ℃ of scopes, temperature between particularly about 1000 ℃ and about 1600 ℃, the temperature between perhaps about 1200 ℃ and about 1500 ℃.They can be directly use in air atmosphere and without any need for the protectiveness blanketing gas.

As alternative dispensing means, the stupalith that floods with graphite or carbon can be used as heating unit.The carbon that is flooded in the ceramic component or the amount of graphite or per-cent can change to adapt to special applications or the resistivity of needs is provided in heating unit.

Heating unit can be packed in the groove with boron nitride particle, and these particles can be the forms of paste.

In preferred implementation of the present invention, heating unit comprises the carbon fiber of being made by polyacrylonitrile.

Have been found that the commercially available carbon fiber that is used to build model aircraft is specially suitable.

Heating unit can comprise plural number thigh or complex root carbon fiber, and they can weave and form rope sample matrix material.Heating unit can comprise up to about 12000 sub-thread carbon fibers.Carbon fiber can be sealed in the suitable external capsule, and this external capsule can bear the working temperature of well heater and the abominable working conditions of growth room.

Have been found that Toray Carbon Fibres America, the ToraycaTM carbon fiber work that is numbered T300-1000 of Inc supply is good.

The axial thermal expansion coefficient of carbon fiber is approximately-0.4 to approximately-1.0 * 10 ^-6/ ° K.Have been found that-0.41 * 10 ^-6The thermal expansivity of/° K is enough low can be crooked in groove when carbon fiber stands working temperature in the RPECVD growing system to assurance.The length of carbon fiber can be used as and need be calculated by the function of the heat of well heater transmission.The needed total electrical resistance of the well heater that uses in the RPECVD growing system is about 10 to 20ohm.This is useful for keep low voltage and electric current in the growth room.

Carbon fiber can have about 0.1 to about 10 * 10 ^-3The resistivity of Ω .cm.Have been found that weaving carbon fiber comprises about 1000 to about 3000 fibers, the resistivity of every fiber is about 1.7 * 10 ^-3Therefore Ω .cm, this weaving carbon fiber, when it uses the power drives of 50V, produce about 125 to 200 watts heat at the resistance that about 12 to 20 Ω are provided on the length that makes things convenient for of about 31cm.

Carbon fiber is formed in it usually and has unexpected intensity on vertically, and is not for its potential use as the heater heats element.In well heater according to the present invention, intensity is not by special concern, but the special concern specific conductivity.In routine is used, may use some very important carbon fiber characteristics comprise to it, its intensity, modulus, density, homogeneity (mechanical property), to the tolerance of environmental attack and with the consistency of other material.Have been found that these characteristics do not conflict with its purposes that is used as heating unit in well heater according to the present invention usually mutually.

The form of the cable that carbon fiber can be made up of many filaments is handled in the groove of substrate, can be accessed enough intensity when twining around the turning with box lunch, and it can remained in the groove when being electrically connected with well heater foundation with circuit.Carbon fiber preferably weaves in advance to avoid it to be worn when handling and being installed in the well heater.Its thermal conductivity can be about 0.01 to about 0.1Cal/cm.s. ℃, preferably in about 0.025Cal/cm.s. ℃ zone.Its specific conductivity can be about 1000 μ Ω .cm to about 10000 μ Ω .cm,, preferably in the zone of about 1700 μ Ω .cm.

Carbon fiber can be, for example, and Hexcel or Torayca ^TMCarbon fiber.The inventor has been found that the carbon fiber of making and be numbered T300 by Eurocarbon BV provides good result.

Multiple braided cable can obtain by commercial sources from Eurocarbon BV (www.eurocarbon.com).Can use the weaving carbon fiber (3KT300) of light weight or the weaving carbon fiber (6KT300) of medium wt.The diameter of weaving carbon fiber (in about 45 ℃ of measurements) can be the extremely about 15mm of about 5mm, and its weight can be that about 7g/m is to about 20g/m.Thickness when 50%FV can approximately change between the extremely about 0.48mm of 0.31mm.

The carbon fiber of operable other type can be as shown in table 2:

Table 2

The intensity of commercially available PAN based carbon fiber and modulus table

Rank	Tensile modulus (Gpa)	Tensile strength (Gpa)	Producing country
Rank	Tensile modulus (Gpa)	Tensile strength (Gpa)	Producing country	Standard modulus (＜265 GPa) (being also referred to as " high strength ")
?T300?T700?HTA?UTS?34-700?AS4?T650-35?Panex?33?F3C?TR50S?TR30S	?230?235?238?240?234?241?241?228?228?235?234	3.53 5.3 3.95 4.8 4.5 4.0 4.55 3.6 3.8 4.83 4.41	France/Japan Japan German Japanese/U.S. U.S. U.S. U.S./Hungary u.s.a. and japan Japan
	?230?235?238?240?234?241?241?228?228?235?234	3.53 5.3 3.95 4.8 4.5 4.0 4.55 3.6 3.8 4.83 4.41		Medium modulus (265-320 GPa)
?T800?M30S?IMS?MR40/?MR50?IM6/IM7?IM9?T650-42?T40	?294?294?295?289?303?310?290?290	5.94 5.49 4.12/5.5 4.4/5.1 5.1/5.3 5.3 4.82 5.65	France/Japan France Japanese the U.S. U.S. U.S. U.S.	Medium modulus (265-320 GPa)
?T800?M30S?IMS?MR40/?MR50?IM6/IM7?IM9?T650-42?T40	?294?294?295?289?303?310?290?290	5.94 5.49 4.12/5.5 4.4/5.1 5.1/5.3 5.3 4.82 5.65	France/Japan France Japanese the U.S. U.S. U.S. U.S.	High-modulus (320-440 GPa)
?M-40?M40J?HMA?UMS2526?MS40?HR40	?392?377?358?395?340?381	2.74 4.41 3.0 4.56 4.8 4.8	Japan France/Japan Japan Japan Japan Japan	High-modulus (320-440 GPa)
?M-40?M40J?HMA?UMS2526?MS40?HR40	?392?377?358?395?340?381	2.74 4.41 3.0 4.56 4.8 4.8	Japan France/Japan Japan Japan Japan Japan	Ultra high modulus (～440 GPa)
?M46J?UMS3536?HS40?UHMS	?436?435?441?441	4.21 4.5 4.4 3.45	The Japanese U.S.	Ultra high modulus (～440 GPa)

Information source is in manufacturer's database

The source: David Cripps, SP Systems ( Http:// www.spsystems.com)

Be used for the situation of MBE or RPECVD method at well heater according to the present invention, plus heater element can comprise 3 to 20 bundle monofilament, and each Shu Dansi can comprise 50 to 50000 rhizoids.The inventor has been found that the weaving carbon fiber cable serviceability of being made up of 12 bundles (each bundle is made up of 1000 monofilament) is good especially.

The two ends of carbon fiber can be connected with circuit.Connection can be via the wire or the connection piece of platinum or gold.Perhaps, can provide contact via following method: molybdenum sheet is rolled into right cylinder, one end of wire or heating unit is put in the cylindrical end, and its by fastening before on wire end and the heating unit, will contact silk or platinum filament or spun gold and import the cylindrical the other end.

If use platinum filament, it can have enough diameters and enough short length can not increase heating unit significantly with assurance total electrical resistance, because platinum has high relatively resistivity, and if the temperature of heating unit and connection piece be increased to more than the fusing point of platinum, it might melt.

Weaving carbon fiber can in case the blocking fiber skids off groove, and be short-circuited on himself around the curve of groove tractive with sudden force.

The atmosphere that runs in MBE and RPECVD method is reductibility normally.Can not be damaged under the reductive condition that carbon fiber runs in aforesaid method.Embrittlement takes place in its gas that also can not use in RPECVD or MBE method.But when well heater used in oxidizing atmosphere, carbon fiber may have oxidized risk, and using silicon carbide rather than carbon fiber is useful as the material of building heating unit.

Coating

Well heater may further include the heat transfer coating of covering heating elements.The heat transfer coating can be made by sapphire or quartz easily.Its size can prevent or stop condensation on the metal nitride layer of carbon on heating unit evaporation or the substrate in being grown in the growth room at least.

Coating can be heat conduction, so that provide homogeneous and uniform temperature to distribute in the crystal growing process of metal nitride on substrate.

The heat transfer coating can be made by sapphire or quartz.Coating by sapphire or quartzy situation about making in, the transmissivity of the heat of coating is about 60% to about 90%, this depends on its thickness.Thickness can change between about 50 microns to about 2 millimeters.In thickness was about 500 microns situation, transmissivity can be about 85%.Perhaps, thickness can be 100 microns, 200 microns, 300 microns, 400 microns, 600 microns, 700 microns, 800 microns, 900 microns, 1 millimeter, 1.5 millimeters etc.Have been found that sapphire is a kind of good material of building coating because it has high thermal conductivity, and allow most of heat that heating unit produces by radiation delivery to the substrate of growing film thereon.Boron nitride is not good as heating unit coating serviceability.

Coating can not be made by very pure material, as long as wherein there is impurity just can not absorb too many heat.It is about 20% that the amount that heating unit radiating heat coating absorbs preferably is no more than, and more preferably no more than about 15%, further preferably is no more than approximately 10%, further preferably is no more than about 5%.

Supporter

Substrate can be positioned on the supporter of being made by suitable material such as stupalith, aluminum oxide, silicon-dioxide etc., so that well heater and its environment are isolated, and guarantees that most of heat that heating unit produced directly arrives the substrate of generation film growth it on.

Thermopair

Well heater also can comprise the thermopair of one or more measurement temperature.A thermopair can be connected with upper surface of base plate.Another can be connected with the upper surface of coating.

Thermopair can be connected with any part of well heater.One or more thermopairs can be connected with well heater.Another thermopair can be connected with the substrate of growing metal nitride film on it.Another thermopair can be connected with heating unit, although this is not hoped, particularly in the situation that heating unit is made by carbon fiber.For determining when metal nitride film is grown underlayer temperature how thereon, a thermopair can be connected with substrate, another can be connected with any part easily of well heater simultaneously, and the relation between underlayer temperature and the well heater specific part temperature just can be determined in operating process like this.The inventor has been found that can settle the convenient part of thermopair on the well heater is the supporter of substrate.In order to come the calibration substrate temperature with respect to the temperature of heater section, the relation between the temperature of part of other thermopair of having settled on underlayer temperature and the well heater can be measured in certain temperature range, so in normal working conditions, when film is grown on substrate, in the process of Tc relation, thermopair is not connected with substrate, but only connects with its heater section that is connected.

According to an eighth aspect of the invention, provide a kind of method that adds thermal target, this method comprises the steps:

-the resistance substrate that will have a upper surface is placed on target proximity, and wherein this substrate is made by being selected from following material: the compression sintering particle of the nitride of boron or aluminium or carbide or its combination;

-heating unit is placed on the upper surface of substrate or coupled, this heating unit comprises conducting element, the resistance that this conducting element has is enough to produce heat when the heating unit at electric current, and this heating unit is made by being selected from following material: carbon fiber, silicon carbide and flooded the stupalith of graphite; And

-make electric current flow through this heating unit, thus the heat that heating unit is produced is passed to target.

Target can be the substrate that is used for growing gallium nitride, indium nitride or aluminium nitride film in MBE or RPECVD method.

Target can be the substrate of growth regulation (III) the family metal nitride film according to one of preceding method.

Heating means according to the present invention may further include the step with the coating covering heating elements.

According to a ninth aspect of the invention, provide a kind of method of making well heater, this method comprises the steps:

-particulate material the compression that will be selected from the nitride of boron or aluminium or carbide or its combination forms the substrate with upper surface;

-heating unit is placed on the upper surface of substrate or coupled, this heating unit comprises conducting element, the resistance that this conducting element has is enough to produce heat when the heating unit at electric current, and wherein this heating unit is made by being selected from following material: carbon fiber, silicon carbide and flooded the stupalith of graphite; And

-electrical contact that heating unit is connected with circuit (contact) is provided, so that in use make electric current pass through heating unit, thereby produce heat.

Upper surface can be furnished with groove, and can comprise according to the method for manufacturing well heater of the present invention heating unit is placed in step in the groove.

The method of making well heater can comprise that also the end with carbon fiber is connected with chemically inert wire end so that the step of connecting with circuit to be provided.Wire can be made by any suitable metal that is selected from platinum metals.Connection can realize by following method: suitable paper tinsel (for example paper tinsel of being made by molybdenum or platinum metals) band is rolled into pipe, one end of heating unit is inserted in the end of this pipe, and will be inserted the into the other end by the wire that inert material is made, the two ends with this pipe are fixedly clamped on heating unit and two ends wiry respectively.When needs made the well heater operation, wire can be connected with circuit.

According to the tenth aspect of the invention, provide a kind of manufacture method of the well heater that uses in sever atmosphere, wherein this method comprises the steps:

-form resistance substrate from the compression sintering particulate material of the nitride that is selected from boron or aluminium or nitride or its combination; With

-heating unit is placed on the upper surface of substrate or coupled, this heating unit comprises conducting element, this conducting element has certain resistance, produce heat when the heating unit at electric current like this, wherein this heating unit is made by being selected from following material: carbon fiber, silicon carbide and flooded the stupalith of graphite.

Substrate can form from the wafer or the dish cutting of being made by the sintered particles of the nitride of boron or aluminium or carbide or its combination.Substrate can be the form of disk.Then, can or grind thereon in the surface groove processing.

According to an eleventh aspect of the invention, provide a kind of manufacture method of the well heater that uses in sever atmosphere, wherein this method comprises the steps:

-resistance substrate of being made by the compression sintering particulate material of the nitride that is selected from boron or aluminium or nitride or its combination is provided; With

This method may further include the heat transfer coating is placed on step on the upper surface of base plate and/or on the heating unit.

Perhaps, or in addition, coating can be positioned on the supporter.

As further alternative step, substrate can be positioned on the supporter.

Use

Well heater can form the part of RPECVD growing system.The RPECVD growing system goes for the epitaxy of semiconducting nitride thing.

An embodiment according to well heater of the present invention is adapted at about 10 ^-1Torr is to being low to moderate about 1 * 10 ^-7Use in the vacuum of Torr, perhaps even lower, for example 10 ^-8, 10 ^-9, 10 ^-10Torr.Another embodiment can use in abominable oxidizing atmosphere.In this embodiment, preferably use silicon carbide elements.Another embodiment of the invention can comprise in metal nitride semiconductor's process of growth in the environment of free metal organism and nitrogen free radical and using.

Advantage

An advantage according to well heater of the present invention is the cost that has significantly reduced material.

Another advantage is that well heater can quite easily be made, because substrate is made from using Standard Steel topping machanism material processed.

When using the carbon fiber heating unit, it can be applicable to the almost groove of Any shape.

Can in the situation of the abominable gaseous atmosphere of needs radiation heating system, use according to well heater of the present invention.

Description of drawings

By the mode of embodiment, preferred form of the present invention is described with reference to the drawings now, wherein:

Fig. 1 is to use the method according to an embodiment of the invention, at the X-line diffraction analysis of two kinds of GaN samples of growing on the ZnO/ silicon dioxide substrates in 2 θ configurations, this GaN sample is respectively 630 ℃ and 650 ℃ of growths, wherein in X-line diffraction analysis, observed (0002) and (0004) reflection, this performance shows, shows more sharp-pointed FWHM at the sample of 650 ℃ of growths than the sample 630 ℃ of growths;

Fig. 2 (a) and (b) and the surperficial 3D1 μ m that (c) are three kinds of optimization GaN layers ²Afm image, these three kinds of GaN layers are grown on following substrate respectively: a) ZnO/ soda-lime glass substrate, its typical r.m.s. roughness are 19 to 27nm; B) ZnO/ Sapphire Substrate, its typical r.m.s. roughness is 9 to 13nm and 3) the ZnO/ silicon dioxide substrates, its typical r.m.s. roughness is 1nm.

Fig. 3 has shown respectively at the SIMS of 630 ℃ and 650 ℃ Grown GaN films oxonium ion signal, the oxonium ion signal is to show with the ratio of nitrogen ion output, and the oxonium ion signal of aforementioned GaN film and the oxonium ion signal that obtains by MOCVD growth and the commercially available GaN film sample made by EMCORE and TDI are compared;

Fig. 4 has described to use an embodiment of the method according to this invention, on the ZnO/ silicon dioxide substrates light at room temperature photoluminescence density of Grown GaN sample and optical absorption square research;

The mode of Fig. 5 by relatively described two kinds of different GaN samples and with reference to the light at room temperature photoluminescence density spectra of two kinds of commercially available samples mentioning among the figure 3 at short wavelength's band gap place;

The mode of Fig. 6 by relatively described three kinds of different GaN samples and with reference to the light at room temperature photoluminescence density spectra of two kinds of commercially available samples mentioning among the figure 3 at middle band gap place;

Fig. 7 is the vertical view according to the baffle plate of an embodiment of the invention;

Fig. 8 is the side-view that is used for holding according to the shell of the baffle plate of an embodiment of the invention or impeller;

Fig. 9 is the axis side view that waits according to the impeller of one embodiment of the present invention;

Figure 10 is the axis side view that waits that comprises according to the shell of the impeller of Fig. 9 of one embodiment of the present invention;

Figure 11 a is the vertical view that comprises according to the shell of the impeller of one embodiment of the present invention;

Figure 11 b is the side-view according to the baffle plate of one embodiment of the present invention;

Figure 12 a is the schematic diagram according to an embodiment of the device of growth regulation of the present invention (III) family metal nitride film;

Figure 12 b is the schematic diagram according to an embodiment of the device of growth regulation of the present invention (III) family metal nitride film;

Figure 13 is the schematic three dimensional views according to another embodiment of the device of growth regulation of the present invention (III) family metal nitride film;

Figure 14 is the schematic diagram according to an embodiment of the device of growth regulation of the present invention (III) family metal nitride film;

Figure 15 is that the degree of depth that is presented at the gallium nitride film surface that distance grows in the device according to the embodiment of the present invention constantly increases down, the chart of Sauerstoffatom and the ratio of nitrogen-atoms;

Figure 16 is the comparison diagram of atom mass spectroscopy, its shown according to the embodiment of the present invention and in according to the old and new RPECVD of conventional P RECVD method because the background signal that the existence of residual gas produces;

Figure 17 is with respect to the equal graphic representation of side of uptake factor at the gallium nitride film of growing under 1 Torr and the gallium nitride film energy of growing under 3 Torr;

Figure 18 is the diagram elevation of well heater according to the embodiment of the present invention;

Figure 19 is the schematic diagram of substrate that forms the well heater part of Figure 18;

Figure 20 is the photo that shows the front view of the well heater that does not have coating of another embodiment according to the present invention; With

Figure 21 is the photo of front view of substrate that forms the well heater part of Figure 20, and it has shown by the heating unit of being made by weaving carbon fiber that is located in the groove that grinds out in the substrate surface (not having coating).

Embodiment

For Fig. 7, it has shown baffle plate 70, and it is used for preventing substantially that the average energy that produces at nitrogen plasma from arriving substrate more than or equal to the active neutral nitrogen kind of the bond energy of (III) family metal nitride key.Baffle plate 70 has ring texture, and will be arranged in the lower end of the RPECVD web member 1220 that Figure 12 a and 12b show.Baffle plate 70 comprises outside surface 71 and internal surface 72.Annular plate 73 is fixed on the internal surface 72, and this annular plate can be made by boron nitride, and can comprise that a series of holes 74 pass through through it to allow active neutral nitrogen kind.

For Fig. 8, it has shown the side-view of shell 102, and it can hold the baffle plate 70 that shows among the impeller 90 that shows among Figure 10 or Fig. 7.

For Fig. 9, it has shown fan-shaped impeller 90, and it can be used for preventing substantially that the average energy that produces at nitrogen plasma from arriving substrate more than or equal to the active neutral nitrogen kind of the bond energy of (III) family metal nitride key.Impeller 90 is made up of a plurality of sword sheets 92, and these sword sheets misplace (offset) each other so that for the scattering of active neutral nitrogen kind provides the surface, this scattering causes the reduction of active neutral nitrogen kind average energy.In one embodiment, impeller 90 can be fit to rotation.

For Figure 10, it has shown the shell 102 that comprises impeller 90.Shell 102 and the impeller 90 that is positioned at wherein can comprise being used for preventing substantially that the average energy that produces at nitrogen plasma from arriving the device 1222 (referring to Figure 12 a and 12b) of substrate more than or equal to the active neutral nitrogen kind of the bond energy of (III) family metal nitride key.

For Figure 11 a, it has shown that the impeller 90 with sword sheet 92 prevents substantially that with being used for the average energy that produces at nitrogen plasma from arriving the containment structure 110 of substrate more than or equal to the active neutral nitrogen kind of the bond energy of (III) family metal nitride key.

For Figure 11 b, it has shown shell 102, it will comprise the device 1222 among Figure 12 a and the 12b, and this device is used for preventing substantially that the average energy that produces at nitrogen plasma from arriving substrate more than or equal to the active neutral nitrogen kind of the bond energy of (III) family metal nitride key.Shell 102 is forms of baffle plate, and it comprises

projection

103 and 104, and is applicable to and makes active neutral nitrogen kind stream reorientation.Arrow 105 has been described the direction from the active neutral nitrogen kind stream of Nitrogen plasma source.

For Figure 12 a (also having Figure 12 b), it has shown the device 1200 that is used for growth regulation (III) family metal nitride film.This device comprises growth room 1202, and substrate support 1204 is arranged in this growth room, and substrate 1206 is positioned on this support.Substrate support 1204 can be positioned at (not shown) on the well heater.The crystalline structure that substrate 1206 is had is fit to growth regulation (III) family metal nitride film thereon.Vacuum pump 1208 is used for before growth room 1202 forms reaction mixture it being carried out exhaust.This device also comprises sealing-duct 1210 and remote plasma nitrogen source 1212, and this remote plasma nitrogen source comprises microwave power source 1214 (it can be the magnetron that moves) and microwave waveguide 1216 under 2.45GHz.The distance that the position of substrate and plasma body leave between the position in remote plasma nitrogen source 1212 is about 20cm to 25cm.Nitrogen is imported into the sealed tube 1210 from inlet mouth 1211.

Growth room 1202 also comprises near the device 1218 (it can be a shower nozzle) that is used for providing the mixture that contains (III) family metal species (as trimethyl-gallium) substrate 1206.Shower nozzle can be located immediately at the position on the substrate.In one embodiment, shower nozzle can comprise the annulation that wherein has a series of holes.This hole is towards substrate, with allow (III) family metal species on the direction of substrate 1206 through wherein passing through.Annulation allows to advance towards substrate 1206 through the space of ring central authorities from the active neutral nitrogen kind of plasma source 1212.In an optional embodiment, device 1218 can be positioned at an end of growth room 1202.

The effect of remote plasma nitrogen source 1212 and sealing-duct 1210 is to set up and guide the active neutral nitrogen kind RPECVD web member 1220 of flowing through to enter in the growth room, this web member is operationally 1222 relevant with device, and this device 1222 is used for preventing substantially the average energy that produces at the nitrogen plasma active neutral nitrogen kind arrival substrate 1206 more than or equal to the bond energy of (III) family metal nitride key.Be used for preventing substantially that at average energy that nitrogen plasma produces arrives substrate 1206 more than or equal to the active neutral nitrogen kind of the bond energy of (III) family metal nitride key device 1222 can be the baffle plate of being painted in as Fig. 7 and 11b, or the impeller as being painted among Fig. 8 to 11a.Baffle plate can be made by boron nitride, and can comprise plurality of holes.Impeller can be the fan form that comprises the sword sheet, and the effect of these sword sheets can be that the molecule of wherein advancing is applied centrifugal force.

The temperature of the substrate 1206 in the growth room 1202 about 480 ℃ to about 680 ℃ scope, and 650 ℃ of preferably approximatelies.This device can comprise in addition that laser 1226 is to bring out the deposition of (III) family metal nitride on substrate that is formed by reaction mixture.

In use, vacuum pump 1208 is used for realizing about 10 in the growth room ^-7The pressure of Torr.Then, in the process of vacuum take-off, substrate is heated to about 650 ℃ growth temperature.When reaching required pressure, film growth can begin.Plasma source gas will (nitrogen) is imported the top of sealing-duct 1210 via inlet mouth 1211, it carries out ionized by microwave power source (microwave power source) 1214.By importing gas, the pressure in the growth room is remained on 3 Torr.Microwave power source 1214 is opened to start plasma body.Plasma body comprises high-energy electron and ion and electrically neutral atom nitrogen and the dinitrogen that is excited.Electronics and energetic ion are in the outside decay rapidly of plasma generating area, therefore these species-dinitrogens march to through the RPECVD web member and are used for preventing substantially that the average energy that produces at nitrogen plasma from arriving the device 1222 of substrate 1206 more than or equal to the active neutral nitrogen kind of the bond energy of (III) family metal nitride key, and this device 1222 can be the impeller unit of being painted among impeller unit such as Fig. 8 to 10 or Figure 11 a.Now, plasma body begins operation, and (III) family metal species (it can be a trimethyl-gallium) are imported into through shower nozzle 1218, make film begin to grow on the surface of substrate 1206.It should be noted that in this embodiment, ammonia or hydrogen (except the situation of the hydrogen that adds as trimethyl-gallium) can not be injected towards in the growth room 1202.

In the device of in Figure 12, describing, plasma source a long way off, that is, the substrate that film is grown thereon is not immersed in the plasma body.As mentioned above, the plasma species that is produced by this source is a high activity, and can cause the damage of film when film contacts with these species.These species comprise high-energy electron and ion, add electrically neutral atom nitrogen and the dinitrogen that is excited.The position of substrate and nitrogen plasma leave between the position in the zone that produces nitrogen plasma and have some distances (～20 to 25cm), and energetic ion and electronics are promptly decayed in the outside of plasma generating area, and they can not arrive substrate like this.VISIBLE LIGHT EMISSION from plasma body is limited within plasma generating area self and the so-called twilight sunset district.The zone of the accommodating substrates VISIBLE LIGHT EMISSION relevant with plasma body not in the growth room is because the gas molecule that is present in the growth room is under the following pressure: guaranteeing that with the collision of low energy activity neutral nitrogen kind the energetic ion species are limited near the zone of plasma generation under this pressure.

For nitrogen plasma, the first stage ionization current potential is 14.53eV.When all nitrogen plasmas all fell so far under the energy, further visible light plasma emission can not take place.Therefore, arrive the energy of the neutral atom nitrogen of substrate and the dinitrogen that is excited less than 14.53eV.For the growth of the GaN under the pressure of 3Torr, have been noted that shower nozzle 1218 places in Figure 12 import trimethyl-gallium, cause the strong VISIBLE LIGHT EMISSION relevant with the existence of gallium.The first stage ionization of gallium can be 6.00eV, therefore on the gallium atom average energy of incident neutral nitrogen kind greater than 6.00eV.But, because the position of substrate and nitrogen plasma leave the combined effect of the use of relation between the regional position of nitrogen plasma generation and baffle plate or impeller in the pressure in the growth room, the growth room, this emission can not arrive substrate, therefore, the average energy of the active neutral nitrogen kind of arrival substrate is less than 6.00eV.The bond energy of GaN is about 2.2eV, therefore the active neutral nitrogen kind of incident should have the energy that is lower than this numerical value slightly ideally on the film surface of growth, to prevent that nitrogen dissociates from this surface in thin film growth process (that is, preventing in thin film growth process damage) to crystalline structure.Pressure in the growth room (for example can be adjusted to suitable numerical value, than higher numerical value in the situation that film can be damaged in process of growth) to guarantee satisfying this condition (promptly, be lower than the bond energy of the film of growing, in the situation of GaN film, be lower than about 2.2eV), because under elevated pressures, more collision takes place between active neutral nitrogen kind that is excited and low energy species of gases, thus the energy decreases of the species that cause being excited.Perhaps, the distance that substrate and nitrogen plasma leave between the regional position of nitrogen plasma generation (for example can be regulated, the outlet position and the distance between the substrate of silicon-dioxide sealed tube can be adjusted in the situation that can be damaged than film in process of growth more longer) to guarantee satisfying this condition (promptly, be lower than the bond energy of the film of growing, in the situation of GaN film, be lower than about 2.2eV).Perhaps, growth room's internal pressure and substrate and nitrogen plasma leave and all can be adjusted to desired value to guarantee satisfying this condition (promptly apart from the two between the position that nitrogen plasma produces the zone, be lower than the bond energy of the film of growth, in the situation of GaN film, be lower than about 2.2eV).If there is the active neutral nitrogen kind of q.s to flow to the nitrogen of GaN surface, then can adapt to energy, but this situation is not an ideal a little more than 2.2eV to recover damage.The average energy that arrives the neutral atom species of substrate can the same with the heat energy of substrate low (determining by the temperature on the substrate).The average energy of the molecular species that is excited with N-N bond energy of 9.8eV does not cause the film damage too high for participating in growth for Thin Film, unless for the low energy dinitrogen, the lip-deep molecular dissociation of katalysis supporting film to a certain degree.When needs make the film quality optimizing of being produced, arrange and specified substrate and nitrogen plasma leave nitrogen plasma and produce distance between the regional position for specified impeller, must determine the optimum pressure that in the growth room, uses.For determining this pressure, must carry out repeatedly repetition test, wherein in each physical property of testing the film of post analysis acquisition.

By adjusting the pressure of growth room, might adjust the average energy of the active neutral nitrogen kind of from plasma body, sending, thereby influence the characteristic of (III) family metal nitride film.For example, during limpid substantially and no xanchromatic high-quality thin film, pressure will be set in about 3Torr, and substrate is 25cm with the distance that nitrogen plasma leaves between the regional position of nitrogen plasma generation when needs production.Perhaps, prepare the film with insulation characterisitic if desired, pressure can be low to moderate about 1Torr, and apart from being 25cm, so that make more high energy species arrive substrates.

The result that this average energy is adjusted performance is, when on the substrate with zinc bloom buffer layer (its cohesive strength is about 1.61eV) during growing film, can improve the original pressure of growth room, prevent that like this average energy from arriving zinc oxide film and causing damage greater than the species of 1.61eV.In case film begins growth and (III) family metal nitride layer covers buffer layer, then reduce pressure so that increase the average energy of the species that arrive substrate.

When growth regulation (III) family metal nitride film, the average energy of chemically active species need be remained on the heat energy of substrate.

For Figure 12 b, it has shown a kind of device, its according to Figure 12 a further comprise be used for multiple (III) family's metal species or even hotchpotch introduce the device of growth room.Therefore, the present invention's blended (III) family metal nitride film of also growing, for example, aluminium gallium nitride alloy, InGaN etc.Shower nozzle 1218 is connected with an end of conduit 1219, and the other end is connected with divider 1221.Divider 1221 has a plurality of imports 1223,1225 and 1227 to import multiple (III) family's metal species or doping agent, for example trimethyl indium, trimethyl-gallium, trimethyl aluminium, front three amine alane (trimethylaminealane), triethyl-gallium etc.; The perhaps p-type hotchpotch of GaN, for example for GaN, calcium, beryllium, carbon or magnesium (by adding bis-cyclopentadiene magnesium); Perhaps for n-type GaN, hotchpotch is silicon, oxygen, selenium, sulphur, tellurium or germanium.In the situation of gan, because its low ionization level, overactivity efficient (surpassing 90% in most applications) and low diffusivity, the adulterated optimal selection of n-type is a silicon in thin film growth process.Mix for the p-type, in thin film growth process, use magnesium or calcium hotchpotch to reach maximum concentration.The add-on of (III) family metal species can be for adding about 1 courtyard in about every 1200-2500 the active neutral nitrogen kind atom, perhaps about 1: 1200,1: 1500,1: 1700,1: 1800,1: 1900,1: 2000,1: 2100,1: 2200,1: 2300,1: 2400 or 1: 2500.

Figure 13 has shown the device 310 according to gallium nitride film growth of the present invention.Device 310 comprises feed compartment or preliminary vacuum lock 312, accommodating substrates after it is applicable to and removes from growth room 314 before use sample transfer device 316 imports in the growth room 314 by growth room's import 314.1 substrate or with substrate.Sample shifts on transferable sample holder 317.

Feed compartment or preliminary vacuum lock 312 can be the forms of cylindrical tube, and it is furnished with upper inlet, flange 312.2 and the flange on its near-end 312.3 on its far-end (with respect to growth room 314) that hides with lid 312.1.

Flange 312.3 is provided with passage, and the arm 316 of sample transfer device 316.1 extends by this passage.

Feed compartment or preliminary vacuum lock 312 link to each other with preliminary vacuum lock vacuum system 318, and this system design produces vacuum in feed compartment or preliminary vacuum lock 312.Vacuum system 318 comprises one group of preliminary vacuum lock vacuum valve 318.1,318.2, it is functionally connected to feed compartment or preliminary vacuum lock 312 in the following manner: this mode of connection allows to make when needed air admission feed compartment or preliminary vacuum lock 312, maybe isolates feed compartment or preliminary vacuum locks 312 when sample transfer was prepared sample to growth room 314 when needs.

The growth room can keep apart from feed compartment or preliminary vacuum lock 312 by the mode of growth room's sluice valve 320.

When needs, can in the growth room, produce vacuum by the mode of growth room's vacuum system 322.The growth room is furnished with growth room's vacuumometer 324, and the pressure in the growth room 314 can be measured like this.By the pipe 326 that links to each other with shower nozzle 327, trimethyl-gallium and hotchpotch can be imported in the growth room.

Transferable sample holder 317 is placed on the top of well heater 328, the support that the latter originally experiences the heater platform 330 in the growth room 314.Provide well heater 328 so that when needed sample is heated to temperature up to 750 ℃.The temperature of thermopair 332 with measure sample support 328 is provided.Well heater 328 can be the well heater of seventh aspect present invention.

In thin film growth process, the pressure in the growth room 314 can be controlled by the mode of pressure controlled valve 334.

Active neutral nitrogen kind can import in the growth room by the plasma body sealed tube of being made by quartz 336.Microwave source 338 nitrogen of 1 part/1,000,000,000 parts of impurity (for example less than) ionization so that the nitrogenous source 339 that purifies with relevant waveguide 340 is provided, thereby forms plasma body, this plasma body also contains the electric neutrality chemically active species except that ionizing particle and electronics.The electric neutrality chemically active species imports in the growth room 314 through sealed tube 336.

In use, with air after air inlet valve 318.1 imports feed compartments 312, sample imports by removable lid 312.1.

Preliminary vacuum lock vacuum system 318 is kept apart from feed compartment through preliminary vacuum lock segregaion valve 318.2, imports air by valve 318.1 simultaneously.

Sample be loaded on the sample holder 317 and place feed compartment or preliminary vacuum lock 312 in.Then, close feed compartment air inlet valve 318.1, and in position place lid 312.1.

Open preliminary vacuum lock segregaion valve 318.2, and 318 pairs of feed compartment 312 step-downs of preliminary vacuum lock vacuum system.

In case vacuum drop is low to moderate low value (for example, 10 ^-2To 10 ^-3Torr), preliminary vacuum lock pump segregaion valve 318.2 cuts out; Then, growth room's sluice valve 320 is opened, and uses sample transfer device 316 that sample and graphite sample support are shifted in the into main growth room 314.

Then, sample holder 317 (with sample) is placed on the heater platform 330 (it supports well heater 328).

Then, 314 remove sample transfer device 316 from the growth room, and close growth room's sluice valve 320.

By the vacuum system that comprises turbo-pump bled separately in growth room 314, this turbo-pump is standby by rotor pump, interconnects by turbine-rotary valve.The growth room links to each other through the turbine sluice valve with vacuum system.

In this operational phase, turbine sluice valve and turbine-rotary valve are opened, and pressure controlled valve cuts out.

Then, growth room 314 is reduced to its pressure of foundation.Main growth room 314 is except the situation of repair and maintenance, no longer to atmosphere opening.

During this vacuum suction, sample is heated to growth temperature (about 650 ℃), with thermopair 332 monitoring heater temperatures.Thermopair 332 is imported into by the vacuum feedthrough, and the well heater junctor is also become owner of in the growth room by feedthrough in its vicinity.

When reaching good basis pressure, film growth can begin.Plasma source gas will (nitrogen) is imported into the top, chamber through the plasma body sealed tube, and it carries out the ionized of nitrogen by microwave source 338.

Open microwave source to start plasma body.The energetic ion that produces in the plasma body is decayed rapidly, and can not leave plasma generating area.Free radical that life-span is long and Nitrogen Atom can be advanced outside plasma body head-on collision district, and can be reflected at generation nitride material on sample and the sample holder with metallorganics.

Metallorganics is imported into by the gas pipeline 326 that is connected with 314 tops, growth room with the dopant source gas.

When gas was imported into main growth room, turbine sluice valve and turbine-rotation pump valve cut out, and pressure controlled valve is set at the maintenance constant voltage.

Pressure in the chamber vacuumometer 342 monitoring thin film growth processes.

In an optional purposes of device shown in Figure 13, by removable lid 312.1 substrate (it can comprise buffer layer such as zinc oxide) is directed on the substrate support 317, this substrate support 317 is placed in feed compartment or the preliminary vacuum lock 312 at first.Preliminary vacuum lock vacuum system 318 is isolated from feed compartment or preliminary vacuum lock 312 through preliminary vacuum lock segregaion valve 318.2, and air is imported into by feed compartment air inlet valve 318.1 simultaneously.Close feed compartment air inlet valve 318.1 then, and place lid 312.1 at correct position.Open preliminary vacuum lock segregaion valve 318.2, and preliminary vacuum lock vacuum system 318 is depressurized to feed compartment or preliminary vacuum lock 312 and is lower than 5 * 10 ^-2The pressure of Torr.Then, preliminary vacuum lock vacuum system 318 is isolated from feed compartment or preliminary vacuum lock 312.In case vacuum reaches about 10 ^-2To 10 ^-3The value of Torr (although preferred lower level), preliminary vacuum lock pump segregaion valve 318.2 cuts out, open growth room's sluice valve 320, use sample transfer device 316 that substrate support 317 is transferred to main growth room 314, and be placed on the heater platform 330 (it supports well heater 328).Then, sample transfer device 316 is withdrawn from from growth room 314, closes growth room's sluice valve 320, so that it is isolated from feed compartment or preliminary vacuum lock 312.By the vacuum system that comprises turbomolecular pump bled separately in growth room 314, this turbo-pump is standby by rotor pump, interconnects by turbine-rotary valve.Growth room 314 links to each other through the turbine sluice valve with vacuum system.In this operational phase, turbine sluice valve and turbine-rotary valve are opened, and pressure controlled valve cuts out.Can reach about 10 ^-7The vacuum of Torr.

Then, well heater 328 is set in required temperature to finish growth for Thin Film, this temperature can be about 650 ℃ for gallium nitride film.Well heater 328 can be the type that shows among Figure 18 to 20.Near for being positioned at the well heater 328 thermopair 332 can use typical curve to come the sample estimates temperature.Before growth, must keep about one hour the heat-up time of substrate (for example, comprise can at the substrate of 650 ℃ of remollescent glass forms), with the decomposition of the ZnO buffer layer avoiding occurring after 650 ℃ of following long periods.The evidence that ZnO decomposes is to observe ZnO and change into conduction state from state of insulation after being exposed to 650 ℃.The partly cause that this change takes place is that oxygen runs off from ZnO.Under serious situation, ZnO can run off together.Spend the night or the longer time if substrate is placed, sample can remain under about 300-400 ℃ the lesser temps.Under this temperature, by a little less than the substrate surface desorb in conjunction with impurity (especially water vapour), the vacuum of growth room 314 is enhanced.Once in a while, film growth takes 400-600 ℃ lesser temps to reduce the decomposition of ZnO buffer layer at first, covers ZnO until the gan protective layer.Then, temperature is increased to higher final growth temperature so that quicken film growth.Substrate can remain on the temperature that film will be grown, until reaching at least 5 * 10 ^-6The vacuum of Torr.If substrate is approximately keeping for some time in 300-400 ℃ the temperature range, the time that then needs to be no more than 1 hour under the temperature that film will be grown reaches at least 5 * 10 ^-6The vacuum of Torr.Substrate should keep in the temperature that film will be grown 1 hour at least so that make sample temperature stable.

The slight decomposition of ZnO buffer layer can be tolerated, in fact makes ZnO decompose some a little and is good, and can guarantee the n-type electric conductivity of this layer like this.Therefore, although certain otherwise damage ZnO buffer layer can promote also can to begin film growth under the condition that GaN grows.The growth pressure that is higher than 3Torr is preferred, so that prevent the damage to the ZnO buffer layer.

In case reach at least 5 * 10 ^-6The vacuum of Torr, film growth can begin.Plasma gas source (nitrogen) is directed into the top of growth room 314 through plasma body sealed tube 336, accepts the ionized energy that obtains by microwave source 338.

Growth for gallium nitride film, can import the nitrogen of 600 standard cubic centimeter nitrogen flow velocitys (sccm) through plasma body sealed tube 336, in this case wherein nitrogen through impeller (its as Fig. 9 in institute paint, but be not presented among Figure 13), carry in the zone of 4 inch diameters.

In case nitrogen begins to flow, turbine sluice valve and turbine-rotation pump valve cuts out, and turbo-pump is shut down.Then, nitrogen is directly drained into rotor pump from indoor by self-acting valve.Pressure in the high precision Baratron pressure warning unit monitoring growth room 314.The pressure of preferred growth chamber 314 is set in about 3Torr, this valve will remain on this numerical value about 1% within.

After air-flow begins to flow and sets processing temperature, substrate temperature can reequilibrate to growth temperature (for example, 650 ℃) several minutes.The thermal conductivity of air-flow will influence underlayer temperature at once, so growth temperature can need to be conditioned to be fit to this temperature.Also need begin to make nitrogen flow through the 5-10 of system minute before the growth, so that blow any oxygen species of taking that outside gas delivery system, accumulate off at film.

Before beginning growth about 10 minutes, pipe 326 and shower nozzle 327 can use vector gas (for example, nitrogen) by walking around the gas pipeline (not shown) cleaning of growing system.Its effect be wash out any accumulation take the oxygen species.

In this stage, nitrogen plasma will burn, and be enough to prevent active neutral nitrogen kind damage film in growth under the pressure of 3Torr in the process of gallium nitride film growth.In thin film growth process, substrate can rotate or not rotate.

Now, (III) family metal species by bypass duct through manage 326 and shower nozzle 327 switch to the growth room.When with the flow velocity gallium nitride film growth of 5.0sccm, can use trimethyl-gallium as the gallium source, wherein trimethyl-gallium is carried among the nitrogen stream with the ratio of about 1 trimethyl-gallium atom in about per 250 to 2000 nitrogen-atoms.Also can use other to take the gallium species, for example gallium trichloride and hydrogenation gallium must prepare in the growth room although the survival time in one source, back is too short, because it can not be saved any appreciable for some time.In optional embodiment, also can use the metallorganics species of indium and aluminium.It it should be noted, also will avoid entering any molecular hydrogen of growth room, because can influence the carrying capacity of environment (conditioning) of growth room with hydrogenation gallium source.

Along with the burning of plasma body, (III) family metallorganics kind enters the growth room, and film growth begins.

Growth is 4 hours under described growth conditions, obtains the film of 0.5 micron thickness.By carrying higher power, perhaps use different excitaton source (it can more effectively produce this species), thereby can reach higher growth velocity by increasing the number of the active neutral nitrogen kind that produces in the plasma body to plasma body.

When the film growth phase finishes, once more (III) family metallorganics kind is switched to bypass duct, it can not flow in the growth room like this.Then, with the substrate cooling, Nitrogen plasma source is still opened, because the nitrogen loss can take place sample surfaces under growth temperature and vacuum condition.Because plasma source is still opened, and has avoided the loss of this nitrogen from the surface.When temperature drops to below about 300-400 ℃, close plasma body, nitrogen stream temporarily is conducted through turbomolecular pump.Open turbomolecular pump, close plasma flow.Then, the pressure of growth room is reduced to background pressure.Be lower than 100 ℃ temperature in case sample is cooled to, the sluice valve between preliminary vacuum lock and the main growth room reopens that (use the same steps as with above-mentioned load substrates, the pressure of preliminary vacuum lock has been reduced in advance is lower than 5 * 10 ^-2Torr), and with sample remove and be transferred to feed compartment or the preliminary vacuum lock 312 from well heater 328.Then, growth room's sluice valve 320 between preliminary vacuum lock and the growth room cuts out, the preliminary vacuum lock is vented to normal atmosphere through preliminary vacuum lock vacuum valve 3 18.1, so that remove substrate support 317 from feed compartment or preliminary vacuum lock 312, this substrate support 317 comprises the substrate that has film on it.

Before gallium nitride film begins growth or in the process of growth, can use the method described in the following embodiment 7, so that reduce the oxygen contamination that can cause by pipe.Can handle in 20 to 48 hours by sealed tube 336 operations by making nitrogen plasma.This process can followingly be carried out: growth room 314 is pumped down to about 8 * 10 ^-8To 2 * 10 ⁶The pressure of foundation of Torr (if begin to bleed from normal atmosphere, then bleeding at least 16 hours) imports the nitrogen that purifies advance in the growth room by plasma body sealed tube 336 then.Then, nitrogen plasma burning, system kept 20-48 hour at following state: with nitrogen ion and free radical bombardment sealed tube 336 internal surfaces and with its reaction.

For Figure 14, it has shown a kind of device 10 according to the embodiment of the present invention.Device 10 comprises the silica tube 12 that is used to hold nitrogen plasma, this nitrogen plasma is to produce by the electric field that makes the ultrapure nitrogen that imports silica tube 12 through inlet pipeline 14 stand silica tube 12 inside, this electric field is caused by following microwave: this microwave is produced by magnetron 16, and is fed to silica tube 12 by waveguide 18.

Silica tube 12 is connected with growth room 20, and gas is discharged to vacuum system by exporting 22 from this growth room.

In the growth room, provide well heater 24, to heat the substrate of gallium nitride film growth thereon.

The gas tip 26 of the metallorganics steam in containing metal source (being selected from gallium, aluminium and indium) on substrate heater 24 imports.

In use, before gallium nitride film is grown in growth room 20, at first will install 10 and be vented to about 10 by exporting 22 ^-6The vacuum level of Torr and this device is prepared.After the exhaust, with heating zone or allied equipment (it can apply from the outside) will install 10 assembly be heated near or surpass 100 ℃ temperature, to drive away any moisture that may be present in the device 10.Perhaps, can use internal heater to finish this purpose.When vacuum drop to＜10 ^-6Torr imports nitrogen and produce plasma body in silica tube 12 by inlet pipeline 14, can make pipe 12 passivation like this.Passivation Treatment continues for some time, and this time range can be several hours to several days, and this depends on whether the inside of silica tube 12 and growth room 20 has contacted air and the moisture under the normal atmosphere, and depends on the vacuum level that obtains before the Passivation Treatment.

For Figure 15, it has shown four traces, article one, demonstration is by the gan sample of RPECVD method 630 ℃ temperature growth, another demonstration is by the gan sample of RPECVD method 650 ℃ temperature growth, and the two other trace shows the commercially available GaN sample that Emcore company and TDI company grow by MOCVD.

It is also noted that the gan sample of growing 630 ℃ temperature has much higher oxygen/nitrogen-atoms ratio in the most of plateau region away from the surface than the gan sample of growing 650 ℃ temperature.This is because specific growth rate is lower mutually with 650 ℃ of samples for 630 ℃ of samples, therefore higher oxygen takes place in the process of growth of 630 ℃ of samples mix.But for two kinds of RPECVD samples, the oxygen in most of sample is presented between typical case's measurement level of the existing commercially available GaN material of growing by MOCVD.

For traditional RPECVD method and the method according to this invention, the waste gas of vacuum pump (or residual gas) all uses quadrupole mass spectrometer RGA to carry out residual gas (RGA) analysis.The result is plotted among Figure 16.

As can be seen, for the film sample of growing in legacy system, the peak appears at 44 places.It can be CO by ownership ₂And/or N ₂O.

Film sample for growing in system according to the present invention is caused by nitrogen at the peak at 28 places.

For the film sample of growing in legacy system, peak and water at the 16-19 place close.

For the film sample of in legacy system, growing, may be because the Prevent Carbon Contamination on the residual gas analyzer causes at the peak at 12 places, therefore irrelevant with the method according to this invention.

For two kinds of samples, cause by hydrogen at the peak at 2 places.

The metal nitride film of growing on substrate according to the present invention goes for the device purposes, and for example: LED comprises p-n junction LED, blue-ray LED (comprising GaN LED), double heterojunction LED and metal-insulator layer-semiconductor LED; General lighting is used; Laser diode; SIS device, photoelectric detector; And transistor, comprise bipolar transistor and field-effect transistor; And other appropriate device.Method of the present invention can be used to prepare electronics and PHOTONIC DEVICE.

In Figure 18, it has shown according to well heater 10 of the present invention.Well heater 10 comprises the plate-like compression nitrogenize borosilicate substrate 12 with upper surface 14, has been processed with groove 16 therein.Groove 16 has first end 18 and second end 20.First end 18 and second end 20 all are positioned near discoid substrate 12 centers.

Provide

contact pin

24 and 26 with additional coating 28.(in an optional embodiment, groove or flank that contact

24 and 26 can replace with the far-end that is positioned at cylindrical side wall and protrude upward around the boron nitride substrate.Recessed region can hold the sapphire cover plate on work point, in this work point upper cover plate covering heating elements).

Weaving carbon fiber heating unit 30 extends to its second end 20 from first end 18 of groove 16.For avoiding confusion, in Fig. 2, do not show weaving carbon fiber heating unit 30.

Coating 28 is made by sapphire, and is conductive (transmissive) to weaving carbon fiber heating unit 30 radiating heats in use.In practice, the thickness of coating 28 is chosen as the thermal energy conduction that impurity level in the coating 28 can be able to be allowed to substrate, keeps enough physical strength with normal handling coating 28 simultaneously.

Substrate 12, heating unit 30 and coating 28 all place on the plate-like ceramic supporting body 32, and the latter is an electricity and heat-insulating.Coating 28 upwards is radiated to substrate with heat, and crystal nucleation takes place there.Weaving carbon fiber heating unit 30 is fixed in the groove 16 by coating 28, is short-circuited to prevent heating unit 30 and himself.Coating 28 also can be used for distributing equably the heat that is produced by heating unit 30.

Thermopair can be positioned at the upper surface of coating 28 or need to measure on any other position of temperature.Can further provide a plurality of thermopairs to measure the relation between the well heater each several part temperature.

Under working conditions, in certain temperature range, measure well heater upper surface and/or other parts with respect to the temperature relation between the substrate temperature of growing metal nitride film thereon, like this, when wanting the growing metal nitride film, only just can estimate substrate temperature by the temperature of these parts of well heater.Because the resistivity of heating unit changes in time, and in the situation of carbon fiber heating unit, change in resistance is quite big, when particularly beginning, must recalibrate underlayer temperature and finish temperature relation between the heater block temperature of calibration.

Well heater 10 can be used for remote plasma and strengthen chemical vapour deposition system (RPECVD growing system), in this system from reactant as the reaction mixture of the formation gan of activation nitrogen and trimethyl-gallium in the presence of, gallium nitride film is grown in the growth room.

In use, coating 28 prevents or stops the evaporation and the deposition of steam on the sample that will grow on the substrate of weaving carbon fiber heating unit 30 in the growth room.

In use, well heater links to each other with circuit, and electric current passes through wherein.

When preventing to use for the first time to the damage of well heater, preferably on the surface of heating unit, be heated to gradually about 100 ℃ to about 300 ℃ temperature, 150 ℃ to about 250 ℃ of preferably approximatelies, more preferably about 200 ℃, and in this temperature or aforementioned temperature scope, keep time enough, to guarantee that all excessive water, other material and hydrogen (hydrogen that comprises chemically bound form, for example water) are elevated to working temperature (this temperature can above 1000 ℃) in temperature and are purged before.Time can be 5 minutes to about 24 hours, preferably approximately 30 minutes to about 10 hours, more preferably about at least 1 hour.

At the well heater on period, the temperature of heating unit can be controlled by the electric current that controlling flow is crossed well heater.

Embodiment

Comparative example 1-is exposed to the growth conditions of the inside, growth room that is used for gallium nitride film growth The gold film

To approach evaporated gold film (thin gold film) is exposed in the condition of plasma that uses in the method described in International PCT patent application PCT/AU2003/000598 number.These conditions comprise: the pressure in the growth room is about 1Torr, but does not have the existence of trimethyl-gallium.Use the identical condition of film growth when having trimethyl-gallium to exist, the GaN film that obtains is some yellow a little.For golden film, when with it when its sedimentary glass substrate is peeled off, observed damage.When peeling off this film, glass substrate is in room temperature.Believe that in thin film growth process incident nitrogen kind remains unusual high energy in the remote plasma moving process, although there is sizable distance (approximately 25cm) between plasma source and substrate.

Embodiment 2-uses RPECVD Grown GaN film under 3Torr

Repeat embodiment 1 with gallium nitride film growth.Opposite with 1 Torr that uses among the embodiment 1, use the higher growth pressure of about 3Torr, its objective is the average energy that reduces the active neutral nitrogen kind that arrives substrate.Believe that higher growth pressure produces more gas collisions, thereby reduced the average energy of the active neutral nitrogen kind of incident in gallium nitride film.

As if this variation in the growth conditions is compared on color film with the film of growing under the pressure of 1Torr more transparent immediately.Viewed light yellow being considered in the film of growth in embodiment 1, or the result of some lens lesions because sample is rich in gallium a little.The electrical characteristic of the film of growth are compared greatly with embodiment 1 and have been improved in embodiment 2, and optical characteristics has also improved.

The former inventor of the odds ratio that the raising of film quality will be developed the ZnO buffer layer believes that the degree that may reach is more abundant.The GaN film is in about 650 ℃ temperature growth.The inventor recognize use damage that the RPECVD technology produces than expected in the past big after, be enhanced in the quality of about 650 ℃ temperature Grown GaN film.

Embodiment 3-uses a series of GaN films of RPECVD growth under 3Torr

In device according to the present invention, use the result of the multiple GaN film of the method according to this invention growth be presented at below and discuss.In the method, use lower pressure of foundation (about 10 ^-7Torr), in the gallium nitride film process of growth, keep air-flow is controlled preferably by using pressure valve by manometric Baritron feedback control.The nitrogen flow velocity is about 600sccm/min.Trimethyl-gallium is as being imported into the mixture of the nitrogen carrier gas flow velocity with about 5sccm/min.The amount of trimethyl-gallium and nitrogen carriers is about 1: 2000, and the pressure in the thin film growth process is 3Torr.

Device is different with the device that was used for gallium nitride film growth in the past on its geometrical shape, especially the direction of gas of Yin Ruing and plasma body charging.In employed device, the gas of introducing and plasma body charging are to be directed on the substrate support downwards rather than to pass it.

Be the details of the physicals of (except pressure is changed to 3Torr from 1Torr) two kinds of special gallium nitride films on the ZnO/ Sapphire Substrate under the same conditions below.In two kinds of situations, do not use impeller, growth temperature is 650 ℃, is 150 sccm from the nitrogen stream of plasma body, from trimethyl-gallium/nitrogen stream of sample holder top shower nozzle for 5sccm (1 trimethyl-gallium atom: 76 nitrogen-atoms), at 650 ℃ of pressures of foundation less than 7 * 10 ^-7Torr.

The color sample yellow that first growth under the growth pressure of 1Torr obtains is very obvious, and is that (resistivity is greater than 10 for insulating all ⁴Ohm.cm).The ultraviolet-visible light transmission measurement shows that band gap is 3.35eV, and it is lower than the numerical value accepted of 3.40eV slightly.The inventor has been found that the index of the normally rich gallium material of lower band gap.Equally, under the edge of the ABSORPTION EDGE between 2.9eV and the 3.35eV, evidence is the strong band tailing (seeing Figure 17) in absorption data.

Second growth under the 3Torr growth pressure has produced yellow very shallow sample (it may be owing to the reason of interference fringe rather than lattice defect), and it is highly conductive (resistivity=3.2 * 10 ^-3And have a very high carrier concn 1.2 * 10 ohm.cm), ¹⁹Cm ^-3But the mobility of this carrier concn is very high, is 162cm ²/ V.s.Measured band gap is very high, is 3.55eV, and it is because very high carrier concn has caused slight Moss-Burstein drift.For this sample, to compare with the sample of growing at 1Torr, band tailing significantly reduces.

The inventor to the explanation of The above results is, be higher than the active neutral nitrogen kind of GaN bond energy (for the film of under 1Torr, growing by average energy, it can arrive substrate) damage that produces causes that the tangible nitrogen of this sample runs off, thereby caused xanthochromia and low-energy band gap.High-caliber damage has caused the generation of compensating defective, and it has greatly increased the resistivity of sample.Under the elevated pressures of 3Torr, damage has greatly been reduced, and compensating defective is just not too obvious like this, and can reach very high background carrier concn.For this carrier concn, electronic mobility is very high, and the defect level that this representative is relevant with the compensation center is very low.

The test details of embodiment 3

A series of GaN samples are grown in UHV RPECVD system.Before the beginning film growth, the sediment chamber is pumped to about 2 * 10 in advance at 650 ℃ of required underlayer temperatures ^-7The pressure of foundation of Torr.

For all film growths, growth pressure all is 3Torr.Trimethyl-gallium is imported into into indoor by sample holder top annular shower nozzle with the nitrogen carrier gas, flow velocity is 5sccm.Import the nitrogen stream of 150sccm from the top (when using impeller, flow velocity is 600sccm) of growing system by microwave plasma.Growth velocity is about 2 μ m/h.The final thickness of all films is between 0.8 to 2 μ m.The GaN film growth is on various substrates: sapphire, silicon-dioxide, soda-lime glass and borosilicate glass.On all substrates, use the thick ZnO RF sputter buffer layer of 50nm in addition or do not use the research of any buffer layer.

The result

Growth temperature and pressure are important parameters very in the GaN deposition process.Between substrate and substrate support, need suitable thermo-contact.Best GaN film is 650 ℃ of growths.For the growth of carrying out in the temperature of hanging down the several years than this temperature, the crystal mass of GaN film is relatively poor, and showing does not at room temperature have the photoluminescence reaction.Comparing with other substrate, is very deleterious 650 ℃ growths for the soda-lime glass substrate, because the softening temperature of such glass is in close proximity to growth temperature.Carrying out optical absorption on all samples measures.For all samples, the optical energy gap numerical value that optical density (OD) contrast all square and power spectrum [5] obtains is between 3.35 to 3.40eV.The band gap of fixed wurtzite-type GaN is 3.40eV.Example is pictorialization in Fig. 4.

X-line diffraction, AFM, SIMS and photoluminescence are used for measuring the quality of the GaN structure of acquisition.Growth velocity is 0.2 μ m/h.The oxygen level shows the same low with the commercially available GaN sample of growing＞950 ℃ temperature.The photoluminescence on band edge edge also is equivalent to the material of commercially available MOCVD growth.Observed very strong emitting red light for many samples.

X-line diffraction (XRD)

Use PhilipsX ' Pert PRO diffraction system to carry out X-line diffraction (XRD) and measure, use the standard C uK α source of radiation of wavelength X=1.542_.Divergent slit is set in 1/2 °, receives slit and is set in 1/8 °.All GaN films show wurtzite-type (0002) and (0004) reflection.The crystalline orientation that does not have other.For the film of growing on different substrates at 650 ℃, XRD determining result is reported in the following table 1.As in the table 1 as seen, the numerical value that Grown GaN obtains on silicon-dioxide/ZnO substrate approaches the c lattice parameter document numerical value [6,7] of GaN granulated material report most, and has the most outstanding full-width at half maximum (FWHM) value.

Table 1

The detailed content of RPECVD GaN sample XRD (0002) reflection of on different substrates, growing

650 ℃ of Grown GaN on different substrates	2θ(°)	c(_)	FWHM
650 ℃ of Grown GaN on different substrates	2θ(°)	c(_)	FWHM	Sapphire	34.550	5.1926	0.2000
Sapphire/ZnO buffer layer	34.535	5.1952	0.1730	Sapphire	34.550	5.1926	0.2000
Sapphire/ZnO buffer layer	34.535	5.1952	0.1730	Silicon-dioxide/ZnO buffer layer	34.545	5.1933	0.1730
Soda-lime glass/ZnO buffer layer	34.635	5.1803	0.2172	Silicon-dioxide/ZnO buffer layer	34.545	5.1933	0.1730

Fig. 1 has shown two kinds of XRD determining that the GaN sample carries out to growing on same substrate: at the silicon-dioxide with 50nm ZnO buffer layer of 650 ℃ and 630 ℃.Compare with 0.173 FWHM 650 ℃ of Grown GaN, lower at the crystal mass of the film of 630 ℃ of growths, be 0.645 at the FWHM of 630 ℃ of Grown GaN (0002) reflection.In the restriction that is subjected to employed XRD instrument aspect the instrument, and numerical value that may be more indicated than these original measured values is low quite a lot of at the numerical value of the sample of 650 ℃ of growths.

Film morphology

The morphology of sample surfaces is studied with noncontact mode (taping mode) with AFM.The GaN film is polycrystalline normally, except some the film of growing on the silicon dioxide substrates with ZnO buffer layer.According to the substrate type of the GaN that grown on it, the size of crystal grain can change to some extent.Between the optical quality of grain-size and GaN, there is not significant trend.Fig. 2 has shown some 3DAFM1 μ m images of the sample of growing on different substrates.As if sample show the crystallite that some mean diameters are about 20-25nm.When growing on the ZnO/ soda-lime glass, surperficial rootmean-square (rms) roughness of GaN is 19 to 27nm; When growth on ZnO/ sapphire or ZnO/ silicon dioxide substrates the time is 9 to 13nm.When growing on the substrate that is not having the ZnO buffer layer, surperficial rms roughness is dwindled the degree of half.When reaching correct thermo-contact between substrate support and substrate, some samples have reached epitaxy (rms roughness～1nm, sharp-pointed XRD), visible Fig. 2 c) GaN on the ZnO/ silicon dioxide substrates.

Secondary ion mass spectrometry (SIMS) (SIMS)

Use has Cs ⁺The dynamic SIMS of the Cameca 5F system of ionic fluid carries out the SIMS measurement to RPECVD sample and two kinds of commercially available MOCVD samples.Because the RPECVD technology has been used remote plasma and the growth temperature lower than traditional MOCVD, the shortcoming of this technology is in the process of growth that oxygen higher among the GaN mixes.Carrying out these measurements is in order to estimate that the oxygen in the GaN sample mixes in process of growth.Only need to carry out qualitative chemical analysis, calculate the ratio of oxonium ion signal and nitrogen ion signal in every kind of sample, the result is reported among Fig. 3.Commercially available EMCORE sample shows O ⁺/ N ⁺Ratio is minimum.Then, immediate is ratio at 650 ℃ of Grown GaN samples.Sample 630 ℃ of growths shows that the oxygen doping is more, but the concentration of oxygen level still is lower than the viewed concentration of commercially available TDI by the MOCVD growth.

Photoluminescence under the room temperature (PL)

Use the He-Cd laser of 325nm line at room temperature on the GaN sample, to carry out the PL measurement as excitaton source.Its example is, Fig. 4 has shown all square figure of the PL observed value of Grown GaN sample on the ZnO/ silicon dioxide substrates and optical absorption.The all square linear extension (dotted line on the figure) of optical absorption shows that band edge is along being 3.4eV on the x-scale chi.This band edge is along being consistent with PL research to the sample band gap, and the peak signal at its peak also is at 3.4eV.The peak signal of also observing a wide emitting red light of sample is 1.9eV.Fig. 5 has shown the detailed content of the PL of different GaN sample band gaps.Shown that the PL from two kinds of TDI and EMCORE different commercially available MOCVD samples compares.PL result shows that the EMCORE sample has the highest frequency band edge signal.In all RPECVD samples, Grown GaN has obtained the highest frequency band edge signal on silicon-dioxide/ZnO substrate, it is reported that its signal density is half of the commercially available TDI sample of GaN.For RPECVD GaN sample and the commercially available sample of MOCVD GaN, also luminous under the gap in common observed Yellow luminous (YL) zone of research, and be reported among Fig. 6.All GaN samples show all that in this district very wide signal, EMCORE sample signal concentrate on around the 2.2eV, and corresponding to Yellow luminous, the TDI sample concentrates on 1.8eV simultaneously, corresponding to emitting red light.The RPECVD sample shows very wide emitting red light, concentrates on 1.9eV, between two kinds of commercially available samples.The reason of these variations is background doped things different in the GaN sample.Although the Grown GaN signal is lower on the ZnO/ silicon dioxide substrates, the density of these signals is suitable.(＞1.5 μ m) compares with commercially available sample, and RPECVD sample P L signal (in Fig. 5 and 6) is less to be because thickness of sample less (＜1 μ m).

Discuss and conclusion

By RPECVD Grown GaN sample on different substrates, its temperature is lower than traditional MOCVD technology.Observed optical characteristics is suitable.The RPECVD technology is a kind of extraordinary alternative approach of growing GaN.Under these concrete growth parameter(s)s, when 650 ℃ of growths, obtain the GaN material of best in quality.Expect to have the existence of ZnO buffer layer, when on silicon-dioxide, using ZnO, reach optimal results.The GaN sample remains polycrystalline usually, but can be observed epitaxy when reaching thermo-contact preferably between substrate support.SIMS result proof has been controlled the oxygen doping preferably in new upgrading growing system, oxygen level and commercially available GaN sample are suitable.Be recorded in 650 ℃ of room temperature PL under the Grown GaN band gap, it is at almost half of the PL that the commercially available material produces of 1000 ℃ of growths.Use this growing technology, in the equipment assembling, it seems that the cheap and suitable substrate with ZnO buffer layer is the potential surrogate of sapphire and SiC substrate.

The comparative example of embodiment 4-Grown GaN film in without any the situation of passivation

There is not the traditional RPECVD system of preliminary vacuum lock to be pumped to about 2 * 10 ^-5To 2 * 10 ^-6Pressure of foundation between the Torr.The growth room is exposed to surrounding environment (attempting as far as possible to reduce the internal surface of device and contacting of atmosphericoxygen although use nitrogen stream in the process of load sample).Use nitrogen purifier to keep impurity in the nitrogen less than 1 part/1,000,000,000 parts.

When system did not use, the growth room kept contacting with atmosphericoxygen with the internal surface of avoiding device in a vacuum.System pressure maintains under the aforementioned pressure of foundation usually.

For growth for Thin Film, after the growth room closes vacuum pump and with after the nitrogen purge gas flushing, substrate is imported into in the system.Substrate imports by the sample load port, makes nitrogen purge gas continuous flow simultaneously.Close the flushing of nitrogen then, the growth room is pumped to pressure of foundation, simultaneously sample is heated to about 650 ℃ the growth room.Place usually and keep about 16 hours or at least 4 hours to reach good vacuum the growth room.Before the beginning film growth, microwave is produced, successively nitrogen is flowed ionization and form plasma body, thereby start nitrogen plasma by the power supply of opening magnetron.Active specy imports in the growth room by the silicon-dioxide sealed tube.Usually use the nitrogen flow velocity of 150sccm.Nitrogen plasma burning then.

In system, use a spot of ammonia stream (flow velocity is 50sccm), directly be oriented on the substrate downwards.For the sample to growth obtains minimum as far as possible oxygen, this a spot of ammonia stream is seemingly requisite in this system.

Then trimethyl-gallium (TMG) is imported to advance in the growth room beginning film growth in the nitrogen of 10sccm.

When film growth finishes, stop TMG and ammonia stream; Close nitrogen plasma, sample in a vacuum or be cooled to room temperature in the nitrogen gas stream.

Minimum oxygen level is that 1.6 atom % (are equivalent to 7 * 10 in the sample of use this method growth ²⁰Sauerstoffatom/cm ³).

The comparative example of embodiment 5-Grown GaN film after using the nitrogen purge gas passivation

Repeat the method for embodiment 4, condition is identical, handles 1 to 2 day with nitrogen purge gas except sealed tube (being made by quartz), attempts the internal surface of passivation sealed tube.

But the oxygen level of the gallium nitride film of growing in the growth room can not reach under the numerical value that obtains among the embodiment 4.In the similar test that the sealed tube that use is made by sapphire is finished, obtained similar result.

Embodiment 6-is according to the GaN growth for Thin Film of one embodiment of the present invention

Use comprises that the growing system of preliminary vacuum lock imports sample.The pressure of foundation of system is 8 * 10 ^-8To 2 * 10 ^-6Torr.When growth did not take place, main growth room remained under the pressure of foundation, therefore can not be exposed to surrounding environment.Also use nitrogen purifier to guarantee that the impurity in the nitrogen is lower than 1 part/1,000,000,000 parts.With silicon dioxide plasma body sealed tube with after the nitrogen plasma of purification contacts several days time, after initial start, or between the growth circulation several hours, obtain best oxygen level.

1) before film growth, handles the microwave plasma sealed tube, the oxygen contamination from pipe can be minimized like this.

2) simultaneously the growth room is kept in a vacuum, preliminary vacuum is locked to atmosphere opening, and sample holder and the sample that will be grown on the substrate are fed to reinforced sticking.

3) close the preliminary vacuum locking closure then, the preliminary vacuum lock is bled pressure is dropped to about 10-2 to 10 ^-3Torr.

4) pump that will be used for the preliminary vacuum lock is then isolated from the preliminary vacuum lock, opens growth room's sluice valve, and like this, sample holder and sample are transferred on the sample heating device.

5) open and work as sample when being heated to growth temperature to the growth room when preliminary vacuum lock, growth room's pressure is increased to about 10 ^-7The numerical value of Torr.

6) after sample holder and sample are loaded on the well heater, remove reinforced fork from the growth room, close growth room's sluice valve.The growth room that will have sample then is under growth temperature or high slightly temperature lower pumping 4-16 hour.Before film growth, be issued to 8 * 10 in higher temperature ^-8To 5 * 10 ^-6The vacuum of Torr.

7) in process of growth, the nitrogen of 150sccm stream imports in the growth room by the plasma body sealed tube, lights microwave plasma.

8) do not use ammonia stream, but the 10sccm nitrogen that will have a TMG imports in the growing system, so that the beginning film growth.

9) when film growth finishes, stop TMG/ nitrogen stream.Close nitrogen plasma then.System is back to pressure of foundation.

10) cooling sample, the preliminary vacuum lock is bled again reaches 10 then ^-2To 10 ^-3Torr.

11) with preliminary vacuum lock with after its pump separates, open the sluice valve between preliminary vacuum lock and the growth room, sample transfer to preliminary vacuum is locked.

12) close growth room's sluice valve then, the preliminary vacuum lock rises to barometric point, and the growth room still keeps the vacuum constant simultaneously.

13) use secondary ion mass spectrometry (SIMS) (SIMS) to analyze the oxygen contamination of GaN sample.Minimum oxygen level is lower than 0.038 atom % (or 9.6 * 10 ¹⁸Sauerstoffatom/cm ^-3).This numerical value is within the limit value of accurately measuring by SIMS, and (another kind of n type GaN film shows that the carrier concn of measuring is about 10 so in fact to have reached the oxygen contamination that hangs down numerical value ¹⁷Individual carrier cm ^-3, show to reach the oxygen concn that is low to moderate 0.0003 atom %).The GaN sample is the n type.

Embodiment 7-is used for holding the passivation of the pipe of nitrogen plasma

Before film growth, it is processed to reduce the oxygen contamination that may be caused by pipe to be used for holding the pipe of nitrogen plasma.Finish this processing by making nitrogen plasma in sealed tube, move 20 to 48 hours.For finishing this processing, system is pumped to pressure of foundation (if begin to bleed from normal atmosphere, bleeding at least 16 hours).

To purify nitrogen by the plasma body sealed tube imports in the growth room.

The nitrogen plasma that burns then, system placed 20-48 hour under following state: with the internal surface of nitrogen ion and free radical bombardment sealed tube and with its reaction.

The film that is used to subsequent thin film to grow by analysis detects the effect of this nitrogenization.If a large amount of oxygen still are present in the growing system in thin film growth process, transmission spectrum will be indicated the oxygen [8] of these a large amount of (degrees) in the film.

If nitrogenization is incomplete, but the oxygen amount that exists is viewed smaller than transmission spectrum, then uses secondary ion mass spectrometry (SIMS) (SIMS) to identify the oxygen level of film.The electrical characteristic of film show indirectly that also nitrogenization is incomplete, because finish electrical characteristic just will change (that is, along with the nitrogenize that continues, carrier concn descends) until nitrogenization.

In case pipe is by nitrogenize, the lasting use of pipe has guaranteed keeping of nitrogenization.If but expectation pipe contacts with air or the ammonia of high density contacts, the nitride layer on the pipe will be by chemical erosion, and even might be removed.Therefore when being not used in film growth, guarantee to be held in the vacuum, to avoid the repetition nitridation process of having to.

When pipe will be placed a very long time and not in device during the growing GaN film, this pipe will carry out the nitrogenize again of short period of time to eliminate the oxygen that may derive from background water vapor in the growth room in a vacuum.The time of finding nitrogenization is depended between down period the amount with the interactional water vapour of pipe.

Embodiment 8-heating unit

By Toray Carbon Fibres America, the Inc. product supplied is numbered the long weaving carbon fiber of 31cm of T300-100Q, is woven together by 12 strands, and the quality of per unit length is 800g/1000m, and density is 1.76g/cm ³, cross-sectional area is 0.45mm ², its measured resistance is 13.67ohms.In order to determine " to burnout " before at it, how many electric currents are arranged by wherein, make electric current pass through its also increase, can't conduct electricity at about 6 ampere-hours until carbon fiber.The power of this electric current generation is about 350 watts (assumed temperature is high more, and the resistance of well heater is low more) as calculated.

Embodiment 9-is that heating unit is made substrate

The groove that design is used for holding as the carbon fiber of heating unit is formed in the upper surface of compression nitrogenize borosilicate substrate.The carbon fiber heating unit of being made by the weaving carbon fiber of embodiment 1 places groove, and tension is short-circuited heating unit and itself to avoid forming coil.There are not the upward view and the vertical view of the well heater of coating to be presented in Figure 20 and 21.After in the carbon fiber heating unit being inserted into groove, the coating coated carbon fiber heating unit of making by sapphire.Substrate and coating, the carbon fiber heating unit that weaves in the groove is clipped in the middle of it, and they all place on the discous ceramic supporting body.The end of carbon fiber heating unit is connected with circuit, strides each end of heating unit and applies 50 volts voltage, and the temperature of heating unit is raise.In order to prepare to use for some time with metallorganics, then with the carbon fiber that uses in a vacuum after air contacts, the electric current that makes 1 ampere is by its about 1 hour time, make the temperature of carbon fiber increase to about 200 ℃, after this, temperature increased to about 700 ℃ in about 15 minutes.Use thermocouple measuring temperature.

Under about 4.4 amperes electric current, this carbon fiber has produced about 250 watts power, and this power is enough to be used in the RPECVD method on substrate with about 650 ℃ temperature growth.

After 15 film growths, still satisfactory according to the operation of well heater of the present invention.

The use (contrast) of embodiment 10-conventional heater

Comprise that the conventional heater of the heating unit of being made by tantalum only can continue to be used for the growth of two gallium nitride films.In some cases, heating unit becomes fragile, and broken.In other situations, heating unit is by the metal deposit short circuit, and it is overheated to cause.

Reference

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Claims

1. strengthen the method for chemical vapour deposition growth regulation (III) family metal nitride film by remote plasma for one kind, described method comprises the steps:

(c) active neutral nitrogen kind is delivered in the growth room;

2. method according to claim 1, wherein step (e) comprises step (e1):

(e1) under the following conditions at the film that forms (III) family metal nitride on the target that is heated: this condition makes below the low 500meV of band gap of band gap than fixed (III) family metal nitride of measured film, and makes described film be applicable to the device purposes.

3. method according to claim 1, wherein step (e) comprises step (e2):

(e2) under the following conditions at the film that forms (III) family metal nitride on the target that is heated: this condition makes below the low 500meV of band gap of band gap than fixed (III) family metal nitride of measured film, and make described film be applicable to the device purposes, wherein in described forming process, use to be selected from least a in the following condition:

(i) described target in the growth room the position and nitrogen plasma leave the zone that wherein produces nitrogen plasma the position between distance be about 20cm to about 25cm, the pressure wherein said growth room in is approximately between 1Torr and the about 15Torr;

Oxygen partial pressure in the (ii) described growth room is less than 10 ^-4Torr;

Oxygen partial pressure in the (iii) described growth room is 10 ^-4Torr to 10 ^-11In the scope of Tor;

Pressure in the (iv) described growth room is approximately between 1Torr and the about 15Torr;

(pressure in the v) described growth room is approximately between 2Torr and the about 5Torr;

(vi) baffle plate or impeller are between described target and Nitrogen plasma source at a distance; With

(position and the distance at a distance nitrogen plasma between of vii) described target in the growth room is that about 20cm is to about 25cm.

4. method according to claim 2, wherein step (e) comprises step (e3):

(e3) form the film of (III) family metal nitride on the target that is heated, the band gap of wherein measured film is lower by 70 to 40meV than the band gap of fixed (III) family metal nitride, and described film is applicable to the device purposes.

5. method according to claim 3, wherein step (e) comprises step (e4):

(e4) form the film of (III) family metal nitride on the target that is heated, the band gap of wherein measured film is lower by 70 to 40meV than the band gap of fixed (III) family metal nitride, and described film is applicable to the device purposes.

6. method according to claim 1, wherein step (e) comprises step (e5):

(e5) form the film of (III) family metal nitride under the following conditions on the target that is heated: this condition makes this film to be semiconductor film and to be applicable to the device purposes, and wherein said metal is selected from the combination of combination, indium and aluminium of combination, gallium and indium of gallium, indium, gallium and aluminium and the combination of gallium and indium and aluminium.

7. method according to claim 1, wherein step (e) comprises step (e6):

(e6) form the film of (III) family metal nitride under the following conditions on the target that is heated: this condition makes this film to be semiconductor film and to be applicable to the device purposes, wherein said metal is selected from the combination of combination, indium and aluminium of combination, gallium and indium of gallium, indium, gallium and aluminium and the combination of gallium and indium and aluminium, wherein in described forming process, use to be selected from least a in the following condition:

(i) described target in the growth room the position and nitrogen plasma leave the zone that produces nitrogen plasma the position between distance be about 20cm to about 25cm, the pressure wherein said growth room in is approximately between 1Torr and the about 15Torr;

Oxygen partial pressure in the (iii) described growth room is 10 ^-4Torr to 10 ^-11In the scope of Torr;

8. method according to claim 1, wherein step (e) comprises step (e7):

(e7) form the film of (III) family metal nitride under the following conditions on the target that is heated: this condition makes the resistivity of this film about 0.0001 and 10 ⁴Between the ohm.cm, and make this film be applicable to the device purposes, wherein said metal is selected from the combination of combination, indium and aluminium of combination, gallium and indium of gallium, indium, gallium and aluminium and the combination of gallium and indium and aluminium.

9. method according to claim 1, wherein step (e) comprises step (e8):

(e8) on the target that is heated, form the film of (III) family metal nitride, wherein said metal is selected from the combination of combination, indium and aluminium of combination, gallium and indium of gallium, indium, gallium and aluminium and the combination of gallium and indium and aluminium, and the resistivity of wherein said film is about 0.0001 and 10 ⁴Between the ohm.cm, and described film is applicable to the device purposes, wherein in described forming process, uses to be selected from least a in the following condition:

(position and distance about 20cm at a distance nitrogen plasma between the extremely about 25cm of vii) described target in the growth room.

10. method according to claim 1, wherein step (e) comprises step (e9):

(e9) form the film of (III) family metal nitride under the following conditions on the target that is heated: this condition makes this film show the crystallographic structure characteristic of (III) family metal nitride and makes this film be applicable to the device purposes.

11. method according to claim 1, wherein step (e) comprises step (e10):

(e10) on the target that is heated, form the film of (III) family metal nitride, wherein said film shows the crystallographic structure characteristic of (III) family metal nitride, and described film is applicable to the device purposes, wherein in described forming process, use to be selected from least a in the following condition:

12. method according to claim 1, wherein step (e) comprises step (e11):

(e11) form the film of (III) family metal nitride under the following conditions on the target that is heated: this condition makes this film show oxygen concn less than 1.6 atom %, and makes this film be applicable to the device purposes.

13. method according to claim 1, wherein step (e) comprises step (e12):

(e12) on the target that is heated, form the film of (III) family metal nitride, wherein said film shows the oxygen concn less than 1.6 atom %, and wherein said film is applicable to the device purposes, wherein in described forming process, uses to be selected from least a in the following condition:

14. method according to claim 1, wherein step (b) comprises step (b1):

(b1) produce active neutral nitrogen kind in away from the nitrogen plasma of growth room, wherein said plasma body produces from following nitrogen: this nitrogen comprises the impurity that is less than or equals 10 parts/1,000,000,000 parts of nitrogen.

15. method according to claim 1, wherein step (c) comprises step (c1):

(c1) described active neutral nitrogen kind is delivered in the described growth room through sealed tube, described sealed tube comprises the pipe that is selected from silicon dioxide tube, silica tube and boron nitride tube, and described pipe has internal surface.

16. method according to claim 14 is wherein carried out step (a ') before in step (a), step (a ') comprising:

(a ') contacts about 1 hour to 100 hours time at about 10mTorr with nitrogen plasma with at least a portion of described sealed tube internal surface to the pressure of about 100Torr, at least a portion of described sealed tube internal surface is contacted at least a portion silicon-dioxide that makes in the described sealed tube and the nitrogen ionic reaction in the nitrogen plasma with nitrogen plasma, thereby make at least a portion silicon-dioxide to the pressure of about 100Torr, change the chemical species that do not discharge Sauerstoffatom or discharge less Sauerstoffatom at about 10mTorr.

17. method according to claim 1, wherein step (c) comprises step (c2):

(c2) described active neutral nitrogen kind is delivered in the described growth room, make described active neutral nitrogen kind directly lead to the central zone of described target along passage, the position of this passage becomes the angle of 45 degree to the right angle substantially with the plane that comprises described target.

18. the device by remote plasma reinforcement chemical vapour deposition growth regulation (III) family metal nitride film, described device comprises:

(a) growth room;

(b) be selected from substrate and the target that comprises the substrate of buffer layer, described target is positioned at described growth room;

(c) be positioned at the well heater of described growth room, its with described target be heated to about 400 ℃ to about 750 ℃ temperature range;

(d) vacuum system, it is used for from the exhaust of described growth room;

(e) sealed tube of making by quartz, silicon-dioxide or boron nitride, it is communicated with growth room's fluid, and the active neutral nitrogen kind stream that described sealed tube is used for producing at the nitrogen plasma away from described growth room is delivered in the described growth room;

(f) be used in described growth room forming the device of reaction mixture, this reaction mixture comprises (III) family metal species that can form (III) family metal nitride film with the reaction of described nitrogen kind, wherein forms (III) family metal nitride film in that film is applicable under the condition of device purposes on the target that is heated.

19. device according to claim 18, it further comprises:

Be used for operating process with the pressure-controlling in the described growth room at the about 0.1Torr device to the scope of about 10Torr, thereby make described film be applicable to the device purposes.

20. according to the device of claim 18, it further comprises:

Be used for preventing substantially in the process of (III) family metal nitride film growth, arriving the device of described substrate more than or equal to the active neutral nitrogen kind of the bond energy of (III) family metal nitride key, thereby make described film be applicable to the device purposes in average energy that nitrogen plasma produces.

21. device according to claim 18, it further comprises:

Be used to control the device of the oxygen partial pressure in the described growth room, be lower than the oxygen concn of about 1.6 atom % thereby described film is shown, thereby make described film be applicable to the device purposes.

22. device according to claim 18, it further comprises:

Be used for from the device of the described nitrogen plasma of following nitrogen gas generation: this nitrogen comprises the impurity that is less than or equals 10 parts/1,000,000,000 parts of nitrogen, thereby makes described film be applicable to the device purposes.

23. device according to claim 18, wherein said well heater are the resistance heaters that comprises following assembly:

Resistance substrate with upper surface, this substrate are made by the material that is selected from following material or are comprised the material that is selected from following material: the nitride of boron, silicon or aluminium or the compressing grains of carbide or its combination; With

Be positioned at described upper surface of base plate or coupled heating unit, it comprises the conductive component with selected resistance, produces heat when the described heating unit with convenient electric current, and wherein said parts are made by carbon fiber or comprised carbon fiber.

24. (III) family metal nitride film, wherein said film shows the oxygen concn that is lower than 1.6 atom %.

(III) 25. according to claim 24 family metal nitride film, it strengthens the chemical vapour deposition growth by remote plasma.

(III) 26. according to claim 24 family metal nitride film, wherein said film comprises GaN.