CN103050350A

CN103050350A - Preparation method of field emitting cathode

Info

Publication number: CN103050350A
Application number: CN2012105831267A
Authority: CN
Inventors: 王明刚; 王雪梅; 孟宪斌
Original assignee: Qingdao Runxin Weiye Science and Trade Co Ltd
Current assignee: Qingdao Runxin Weiye Science and Trade Co Ltd
Priority date: 2012-12-28
Filing date: 2012-12-28
Publication date: 2013-04-17

Abstract

The invention provides a preparation method of an InN nanowire field emitting cathode. The preparation method comprises the following steps of: at first, growing an InN sample on a Si substrate with a layer of deposited Au by using a CVD (Chemical Vapor Deposition) method; secondly, putting a tungsten boat for containing the Si substrate and high-purity metal In into a quartz tube inside a tube type furnace; thirdly, exhausting the quartz tube by using a mechanical pump, and raising the temperature of the quartz tube to a certain fixed value; fourthly, introducing mixed gas of NH3 and Ar; and finally, naturally cooling to a room temperature.

Description

A kind of preparation method of field-transmitting cathode

Technical field

The invention belongs to the field-transmitting cathode field, particularly a kind of preparation method of field-transmitting cathode.

Background technology

The main difficulty that the FED display device faces all comes from the negative electrode manufacture craft except the problems such as Vacuum Package.The difficult points such as the uniformity of controlling filed emission and stability, reduction drive circuit cost all directly are subjected to the restriction of FED cathode material and structure.Spindt type requirement on devices is made hundreds of " pointed cone adds circular hole " cathode array in a pixel magnitude range.This makes photoetching process and film preparation very complicated, and cost of manufacture is also very expensive.The difficult problem of negative electrode manufacture craft has also caused the uniformity of pointed cone array shape relatively poor, and the device resistance to overturning is undesirable, causes further developing of Spindt type FED very difficult.

Metal material stock ground emission boudoir threshold voltage is higher, and is easily oxidized and affect launch stability; Spindt type Mo metal micro tips array technical difficulty is high, apparatus expensive, complex process; Si field Emission microtip array is because the complexity of the little sharp technique of preparation and the difficulty of large-area manufacturing; Monocrystalline diamond film prepares that difficulty is large, cost is high; The difficult film that obtains large tracts of land, has good uniformity of polycrystalline diamond, nanocrystalline diamond and diamond like carbon, and the also existing problems such as the uniformity of electronic launching point and stability, reliability; The carbon nano-tube main difficulty is how to solve the stability of electron emission and the problems such as assembling of uniformity and cathode construction.So in recent years, an emission research worker is devoted to seek the superior new material of a kind of field emission performance always.At present, researchers' attentiveness concentrates on the wide bandgap semiconductor materials.This is because wide bandgap semiconductor materials has the peculiar property that becomes good filed emission cathode material, and has verified constantly also that experimentally wide bandgap semiconductor materials has more excellent field emission characteristic than metal really.

Summary of the invention

The invention provides a kind of preparation method of InN nano wire field-transmitting cathode, comprising:

Method by CVD is depositing the Si Grown InN sample of layer of Au first;

Before the deposition Au thin layer, deionized water rinsing is used in the first process ultrasonic cleaning in toluene, acetone, ethanol of Si sheet again;

The tungsten boat that fills Si substrate and high pure metal In (99.999%) is put into the quartz ampoule of tube furnace, put successively metal In and Si substrate along the direction of air-flow;

The Si substrate is placed on the lower end of air-flow, and the distance of metal In is 3mm;

Subsequently, with mechanical pump quartz ampoule is bled, the vacuum degree in quartz ampoule reaches 2 * 10 ^-1During Torr, the temperature of quartz ampoule is raised to a certain fixed value;

Lead to again NH ₃(99.999%) and the mist of Ar (99.999%), make the temperature in the stove remain on this fixed value, NH ₃Gas and Ar gas flow be fixed on a certain value, the air pressure of pipe maintains 3.5Torr, the growth 30min;

Naturally cool to room temperature.

Description of drawings

The SEM figure of the InN nano wire sample for preparing under Fig. 1 different condition

Fig. 2 Fig. 2 InN nanometer field of line emission J-E curve (a) and F-N curve (b)

Embodiment

The invention provides a kind of preparation method of InN nano wire field-transmitting cathode, comprising: the method by CVD is depositing the Si Grown InN sample of layer of Au first; Before the deposition Au thin layer, deionized water rinsing is used in the first process ultrasonic cleaning in toluene, acetone, ethanol of Si sheet again; The tungsten boat that fills Si substrate and high pure metal In (99.999%) is put into the quartz ampoule of tube furnace, put metal In and Si substrate; The Si substrate is placed on the lower end of air-flow, and the distance of metal In is 3mm; Subsequently, with mechanical pump quartz ampoule is bled, the vacuum degree in quartz ampoule reaches 2 * 10 ^-1During Torr, the temperature of quartz ampoule is raised to a certain fixed value; Lead to again NH ₃(99.999%) and the mist of Ar (99.999%), make the temperature in the stove remain on this fixed value, NH ₃Gas and Ar gas flow be fixed on a certain value, the air pressure of pipe maintains 3.5Torr, the growth 30min; Naturally cool to room temperature.

At first utilize SEM to study temperature and gas flow to the impact of sample topography.Fig. 1 has provided the SEM figure of the InN sample of the 30min that grown under different temperatures and gas with various flow.

Fig. 1 is at T=550 ℃, NH ₃The SEM figure of the sample for preparing under the condition that/Ar ratio is different, growth time is different.Can find out from Fig. 1 (a) with (b), at T=550 ℃, NH ₃Under/Ar=5/I the condition, grown respectively 90min and 30min sample all do not have typical nano wire nano wire to generate.During without Ar gas, generated typical nano wire, its length is near l μ m, and density is not very large, and this launches for the field is favourable, because density is too large, can cause Field shielding effect.

Fig. 2 is at T=550 ℃, NH ₃The field emission characteristic curve of the InN nano wire of growing in the different situation of the different growth times of/Ar ratio.If the definition current density reaches 10 μ A/cm ²The electric field of Shi Suoxu is for opening the field, can find out from Fig. 2 (a) J-E curve so, the unlatching electric field of the sample corresponding with Fig. 2 (a-c) is respectively 13.6v/ μ m, 12.5v/ μ m and 10.0v/ μ m, and under the electric field of 24v/ μ m, corresponding current density is respectively 1330 μ A/cm ², 3629 μ A/cm ²With 5333 μ A/cm ²Relatively find behind these several the curves of (a) figure, it is minimum that electric field is opened in the field emission of the nano wire of growing under the condition without Ar gas, and the current density that obtains after the match in same electrical is maximum, and this is that diameter is minimum because the length of the nano wire of growing under the condition without Ar gas is the longest.

Can find out from Fig. 2 (b), the F-N curve of InN nano wire and the straight line on the non-traditional format, but nonlinear, and form by two sections.This two sections F-N curve form also reported in the literature, and also obtained such curve form in our the former experiment, and this phenomenon is explained, think since low after the match thermionic emission cause " 71].But we think that herein non-linear is not only is because low after the match thermionic emission causes.We had deposited the thick Au thin layer of one deck 2nm at the Si substrate before grow nanowire.Studies have shown that, eutectic reaction just can occur in Au and Si substrate in the time of 350-360 ℃, thereby forms alloy.The growth temperature of our InN nano wire is 550 ℃, so formed the Au-Si alloy.Because the existence of Au-Si alloy-layer so that electronics will be getted over two interfaces, tunnelling process occurs twice, this also is the nonlinear reason of F-N curve.Because add external electric field at semiconductor, electric field will penetrate semiconductor inside, the osmotic effect of external electric field that Here it is.Because an osmotic effect can be with run-off the straight, the angle of inclination will be directly proportional with field intensity, so the low after the match existence at this two interfaces is unfavorable for electron emission, but under the High-Field, band curvature is larger, and the degree of depth of an infiltration is also just larger.

Claims

1. the preparation method of an InN nano wire field-transmitting cathode comprises:

Method by CVD is depositing the Si Grown InN sample of layer of Au first;

Subsequently, with mechanical pump quartz ampoule is bled, when the vacuum degree in the quartz ampoule reaches 2 * 10-1Torr, the temperature of quartz ampoule is raised to a certain fixed value;

The mist of logical NH3 (99.999%) and Ar (99.999%) makes the temperature in the stove remain on this fixed value again, NH3 gas and Ar gas flow be fixed on a certain value, the air pressure of pipe maintains 3.5Torr, 30min grows;

Naturally cool to room temperature.