CN116209786A - Atomic layer deposition method - Google Patents

Abstract

A film formation cycle in each of a raw material gas supply step (S1), a raw material gas purge step (S2), an oxidizing agent supply step (S3), and an oxidizing agent purge step (S4) is appropriately performed by disposing a film formation object (2) in a chamber (3) of an ALD apparatus (11), whereby an oxide film (21) is formed on a film formation surface (20) of the film formation object (2). In the oxidant supply step (S3), 80% by volume or more of ozone gas is supplied into the chamber (3) so that the exposure amount of the ozone gas to the film formation surface (20) is 1X 10 ⁵ Langmuir or more, the pressure in the chamber (3) is set to 1000Pa or less.

Description

Atomic layer deposition method

Technical Field

The present invention relates to an atomic layer deposition method, and relates to a technique for forming a thin film applicable to a semiconductor device or the like, for example.

Background

As a method for forming a thin film (hereinafter, abbreviated as film formation as appropriate) of an advanced device such as a semiconductor device (e.g., a circuit of a CPU), there are typically vapor deposition, sputtering, chemical vapor deposition (CVD: chemical Vapor Deposition), and atomic layer deposition (ALD: atomic Layer Deposition). Among them, ALD is most excellent in step coverage and compactness, and is necessary as a thin film forming means of the most advanced device (for example, patent document 1).

In ALD, the following 4 steps are mainly repeated: the method includes a step of evacuating the entire chamber (vacuum vessel or the like) including an object to be film-formed (e.g., a silicon wafer), a step of introducing an ALD raw material gas (e.g., TMA (trimethylaluminum)) into the chamber, a step of removing the raw material gas from the chamber, and a step of supplying an oxidizing agent (e.g., water vapor) of the raw material gas to the chamber. By introducing a raw material gas into the chamber and filling the chamber with the raw material gas, the raw material gas having a molecular weight of 1 is adsorbed on the surface of the object to be film-formed, and a molecular layer of the raw material gas is formed on the object to be film-formed.

Then, the oxidizing agent of the source gas is supplied into the chamber, whereby the molecular layer of the source gas formed on the film formation surface is oxidized, and the molecular layer of the oxide film (for example, alumina) of the source gas is formed on the film formation surface. By repeating the above 4 steps, a thin film having a film thickness corresponding to the number of repetitions is formed.

Prior art literature

Patent literature

Patent document 1: japanese patent laid-open No. 2014-057014

Patent document 2: japanese patent laid-open No. 2008-294170

Non-patent literature

Non-patent document 1: abstract Book of 12th ACSIN-21in conjunction with ICSPM21,Tsukuba (2013), public welfare Community applied physical society, 11 th, 4 th, p.98

Non-patent document 2: convertech, processingenuity, 9/15/2018, 9/2018

Non-patent document 3: new Release 2019, "high barrier film formation successfully performed at normal temperature using OER Process technique", [ on net ], 7/13/2020, kagaku Kogyo electric house homepage, internet, < https:// www.meidensha.co.jp/News/News # 03/1231056 #2469.Html #)

Disclosure of Invention

Conventional film formation processes using ALD tend to increase the film formation temperature. For example, in order to sufficiently react TMA with water vapor, it is necessary to heat the object to be film-formed to a relatively high temperature (for example, 300 to 500 ℃). In the case of a compound semiconductor such as GaN or ZnO used in the most advanced device, thin film semiconductor layers having slightly different compositions may be formed in a multilayer manner by using heteroepitaxy or MBE (Molecular Beam Epitaxy) on the film formation surface. These thin film semiconductor layers are likely to deviate in composition due to heating, and thus film formation at low temperature is strongly demanded.

In other most advanced devices, it is considered that the film formation temperature by ALD is preferably from room temperature to 100 ℃. Therefore, the replacement of the oxidizing agent with ozone (O ₃ ) Plasma oxygen, ALD utilizing radicals generated by the oxidizing agent. Ozone can generate O radicals as a powerful oxidizing agent by thermal decomposition, and can be cooled to a low temperature, and even then, it is necessary to heat the object to be film-formed to several hundred ℃. Even when plasma oxygen, which can supply O radicals at first and can be minimized, is used, the temperature is lowered to about 100 to 150 ℃, and further lowering of the temperature is required.

In addition, in the conventional film forming process using ALD, the film forming efficiency tends to be lowered due to an increase in film forming time or the like. For example, in order to form a 1-molecule layer on a surface to be formed by ALD, a step of adsorbing a source gas on the surface to be formed, removing the source gas, and oxidizing a source gas layer (adsorption layer) formed on the surface to be formed is first performed. This process typically takes several minutes. For example, in the case of alumina, the thickness of the 1-molecular layer is about 0.1nm, and therefore, about 100-molecular layers are required for practical film formation at about 10nm, and it takes about 50 minutes even if 30 seconds are required for each 1-molecular layer. For example, in the case of other film forming methods such as CVD, if film formation is performed at about 10nm, film formation can be performed within 1 minute, and thus, the film formation time of ALD is a great disadvantage compared to other film forming methods, and improvement of film formation efficiency (shortening of film formation time, etc.) is demanded.

The present invention has been made in view of the above-described circumstances, and an object of the present invention is to provide a technique that contributes to a reduction in film formation temperature and an improvement in film formation efficiency in a film formation process using ALD.

The atomic layer deposition method according to the present invention is a method for forming an oxide film on a film formation object in a chamber of an atomic layer deposition apparatus, the method including: a source gas supply step of supplying a source gas containing an element constituting an oxide film into the chamber and forming an adsorption layer of the source gas on a film formation surface; a source gas purging step of removing a surplus gas of the source gas supplied in the source gas supplying step and a gas generated by adsorption of the source gas on the surface to be film-formed from the surface to be film-formed; an oxidizing agent supply step of supplying 80% by volume or more of ozone gas into the chamber and oxidizing the adsorption layer formed on the film formation surface; an oxidizing agent purging step of removing the residual gas of the ozone gas supplied in the oxidizing agent supplying step and the gas generated by oxidizing the adsorption layer of the raw material gas from the surface to be formed, wherein the exposure amount of the ozone gas to the surface to be formed is set to be 1×10 in the oxidizing agent supplying step ⁵ Langmuir or more, the pressure in the chamber is set to 1000Pa or less.

In the 1 st aspect of the atomic layer deposition apparatus, the atomic layer deposition apparatus may further include: the gas supply unit may include: a source gas discharge port for discharging a source gas into the chamber, an ozone gas discharge port for discharging an ozone gas into the chamber, and an inert gas discharge port for discharging an inert gas into the chamber.

In addition, the respective steps may adjust the gas flow in the chamber by supplying an inert gas into the chamber.

The amount of inert gas supplied may be adjusted based on the volume or shape of the chamber.

The support portion may have a housing-shaped housing wall that houses the plurality of objects to be formed in a removable manner and is disposed in the chamber, and at least a part of the housing wall may be provided with a ventilation portion that allows passage of gas in the chamber and blocks passage of the objects to be formed.

In the 2 nd aspect of the atomic layer deposition apparatus, the support portion supports the object to be film-formed so as to be movable in two directions opposed to each other along four directions of the object to be film-formed, the gas supply portion has a shower head disposed in the chamber so as to face the object to be film-formed, the source gas discharge port and the ozone gas discharge port of the shower head are disposed so as to face the object to be film-formed in the two directions alternately with a predetermined interval therebetween, and the inert gas discharge port is disposed between the source gas discharge port and the ozone gas discharge port, and the respective steps are performed on the object to be film-formed in accordance with the movement of the object to be film-formed in the two directions.

In addition, an inter-orifice exhaust port may be provided at least any one of the respective orifice spaces of the shower head.

In addition, the support portion may have: one end side roller for winding and supporting one end side of the object to be formed and the other end side roller for winding and supporting the other end side of the object to be formed are supported in a free manner by a roll-to-roll manner.

The support portion may have a support table for supporting the object to be film-formed, and the support table may be movable along the film-forming surface of the object to be film-formed.

In addition, in the shower head, a plurality of pairs of the source gas discharge ports and the ozone gas discharge ports adjacent to each other may be arranged at a predetermined interval in the two directions.

In addition, the shower head may be provided with a plurality of source gas discharge ports arranged in a crossing direction crossing the two directions among the four directions along the film formation surface to constitute a source gas discharge port group, and a plurality of ozone gas discharge ports may be arranged in the crossing direction to constitute an ozone gas discharge port group.

The dimension of each of the spray nozzles of the spray head may be in the range of 1mm to 50mm, and the distance between the spray nozzles and the surface to be film-formed of the object to be film-formed may be in the range of 1mm to 20 mm.

At least one of the spray nozzles of the spray head may have a long slit shape in a crossing direction crossing the two directions of the four directions along the film formation surface.

The amount of the source gas supplied may be 0.0001 to 1sccm per unit length of the source gas outlet in the direction perpendicular to the two directions, and the amount of the ozone gas supplied may be 0.1 to 10sccm per unit length of the ozone gas outlet in the direction perpendicular to the two directions.

In the 3 rd aspect of the atomic layer deposition apparatus, the chamber has: the support part comprises: one end side roller for winding and supporting one end side of a film forming object, the other end side roller for winding and supporting the other end side of the film forming object, a 1 st turn-back roller arranged in a raw material gas treatment furnace, and a 2 nd turn-back roller arranged in an ozone gas treatment furnace are roller-to-roller type structures for freely supporting the film forming object in two opposite directions along four directions of a film forming surface, the object to be film-formed between the one end side roller and the other end side roller is turned back by the 1 st and 2 nd turning back rollers, and is extended in a zigzag manner to be reciprocated and overlapped in the raw material gas treatment furnace and the ozone gas treatment furnace, and a treatment furnace opening through which the object to be film-formed can pass is provided in a position where the furnace wall of each treatment furnace crosses the zigzag object to be film-formed in each passage in the inactive gas treatment furnace when the object to be film-formed moves between the raw material gas treatment furnace and the ozone gas treatment furnace.

In the above-described meandering path of the object to be film-formed, a position adjustment roller may be provided at least one of a position facing the treatment furnace opening between the 1 st folding roller and the treatment furnace opening in the raw material gas treatment furnace and a position facing the treatment furnace opening between the 2 nd folding roller and the treatment furnace opening in the ozone gas treatment furnace.

In the above-described aspect, the cycle of each step of the raw material gas supply step, the raw material gas purge step, the oxidizing agent supply step, and the oxidizing agent purge step may be performed a plurality of times, and different types of raw material gases may be supplied to the film formation object in at least 1 step and the remaining steps of each raw material gas supply step.

In addition, the oxide film may contain Al ₂ O ₃ 、HfO ₂ 、TiO ₂ 、ZnO、Ta ₂ O ₃ 、Ga ₂ O ₃ 、MoO ₃ 、RuO ₂ 、SiO ₂ 、ZrO ₂ 、Y ₂ O ₃ An adsorption layer of any one of the above.

The object to be film-formed may be heated in a range of 100 ℃ or lower, or may not be heated.

In the raw material gas supply step, the exposure amount of the raw material gas to the film formation surface may be set to 1×10 ⁴ Langmuir above.

As described above, according to the present invention, in the film forming process using ALD, it is possible to contribute to a reduction in film forming temperature and an improvement in film forming efficiency.

Drawings

Fig. 1 is a schematic configuration diagram for explaining a schematic of an ALD apparatus 11 applicable to an ALD method according to embodiment 1.

Fig. 2 is a film formation process diagram related to formation of the oxide film 21.

Fig. 3 is a reaction schematic diagram showing an example of formation of the oxide film 21.

Fig. 4 is a pressure change characteristic diagram with respect to elapsed time for explaining an example of a film formation cycle using steps S1 to S4.

Fig. 5 is a graph showing film thickness characteristics of the oxide film 21 when the film formation cycle is performed at various temperatures according to example 1.

Fig. 6 is a graph showing the water vapor permeability characteristics of the PEN film formed with the oxide film 21 according to example 1 with respect to the elapsed time.

Fig. 7 is a graph of leakage current density characteristics of the oxide film 21 according to example 1 with respect to the applied electric field strength.

Fig. 8 is a schematic configuration diagram for explaining a schematic of an ALD apparatus 12 applicable to the ALD method according to embodiment 2.

Fig. 9 is a schematic configuration diagram for explaining a schematic of an ALD apparatus 13 applicable to the ALD method according to example 3.

Fig. 10 is a schematic diagram (sectional view along two directions of a film formation surface) for explaining an example of forming the oxide film 21 by the ALD apparatus 13.

Fig. 11 is a schematic cross-sectional view (a view when the shower head 4a is facing from the front of fig. 9; a view corresponding to a part of fig. 9) for explaining the respective spouts and the like of the shower head 4 a.

Fig. 12 is a schematic configuration diagram for explaining a schematic of an ALD apparatus 14 applicable to the ALD method according to example 4.

Detailed Description

The atomic layer deposition method (hereinafter referred to as "ALD method" as appropriate) according to the embodiment of the present invention is completely different from a conventional ALD method (hereinafter referred to as "conventional ALD method" as appropriate) in which, for example, the film formation temperature is set to a relatively high temperature or radicals generated by an oxidizing agent are used.

That is, the ALD method of the present embodiment is a method of forming an oxide film on a film formation object in a chamber of an atomic layer deposition apparatus (hereinafter referred to as an ALD apparatus as appropriate) using ALD, and each of a source gas supply step, a source gas purge step, an oxidizing agent supply step, and an oxidizing agent purge step is suitably performed using the ALD apparatus.

In the oxidizing agent supply step, the oxidizing agent is supplied into the chamberSupplying 80% by volume or more of ozone gas to a film forming surface so that the exposure amount of the ozone gas to the film forming surface is 1X 10 ⁵ Langmuir or more, the pressure in the chamber is set to 1000Pa or less.

According to this embodiment, for example, even if the object to be formed is not heated or the radical is not used as the oxidizing agent, the source gas adsorbed on the surface to be formed can be sufficiently oxidized, and a desired oxide film can be formed. In addition, since an oxide film can be formed at a low temperature (for example, 100 ℃ or lower) as compared with the conventional ALD method by the ALD method using ozone gas at a high concentration, the oxide film can be formed appropriately not only on a substrate having high heat resistance such as a Si substrate but also on a substrate or film formed of a synthetic resin having low heat resistance.

For example, radicals used in the conventional ALD method have a relatively short lifetime, and therefore, it is difficult to widely diffuse in a chamber, and it is considered that it is difficult to oxidize a raw material gas adsorbed on a surface to be formed in a concave-convex shape. Therefore, the object to be film-formed may be limited to a flat plate-like substrate or the like having a flat film-forming surface, or may be limited to a single-wafer process.

On the other hand, in the present embodiment, since a high concentration of ozone gas is used as the oxidizing agent, the ozone gas can be widely diffused in the chamber, and for example, even if the film formation surface is uneven, a desired oxide film can be sufficiently formed. In addition, a plurality of objects to be formed may be disposed in the chamber, and oxide films may be formed simultaneously for the respective surfaces to be formed. Thus, it is found that the film formation temperature can be reduced and the film formation efficiency can be improved in the film formation process using ALD. In addition, since plasma is not used, it can be said that the oxide film formed is free from plasma damage.

As described above, the ALD method of the present embodiment may be applied to various fields (for example, a film formation field such as ALD and CVD, a modification field, a chamber field, an ozone gas field, an unsaturated hydrocarbon gas field, and the like) as long as the concentration, exposure amount, and partial pressure of the ozone gas in the oxidizing agent supply step are appropriately set, and a desired oxide film can be formed on the film formation surface of the object to be formed, and as examples of which design variations are appropriately referred to in the prior art literature and the like as needed, examples 1 to 4 shown below can be cited.

The following embodiments 1 to 4 are given the same reference numerals and the like for the same contents, for example, and detailed description thereof is omitted as appropriate.

Example 1

< principal constitution of ALD apparatus 11 >

Fig. 1 illustrates an ALD method according to example 1, showing a schematic of an ALD apparatus 11 applicable in this example 1. The ALD apparatus 11 of fig. 1 mainly includes: a chamber (reaction vessel) 3 for removably housing the object 2 to be formed, a gas supply unit 4 for supplying various gases into the chamber 3, and a gas discharge unit 5 for sucking the gas in the chamber 3 and discharging the gas out of the chamber 3. The object 2 to be deposited accommodated in the chamber 3 can be appropriately supported by a support portion not shown, for example.

The gas supply unit 4 includes: a source gas discharge port 41 for discharging a source gas into the chamber 3, an ozone gas discharge port 42 for discharging an ozone gas into the chamber 3, and an inert gas discharge port 43 for discharging an inert gas into the chamber 3. The discharge ports 41 to 43 are provided, for example, at positions facing the object 2 to be film-formed in the chamber 3 (positions above the drawing of the chamber 3 in fig. 1), and are connected to the source gas supply device 41b, the ozone gas generation device 42b, and the inert gas supply device 43b via the pipes 41a, 42a, and 43a, respectively.

In the case of the discharge ports 41 and 43 shown in fig. 1, the discharge ports are unified into one, and are provided as a common discharge port in the chamber 3, and the pipes 41a and 43a are connected together. According to such a configuration, the inert gas of the inert gas supply device 43b can be used as the carrier gas when the raw material gas of the raw material gas supply device 41b is supplied into the chamber 3.

For example, according to a configuration in which a pipe 43c connected to the inactive gas supply device 43b is joined to a pipe 42a (joined as depicted by a broken line in fig. 1) and is connected to the discharge port 42, the inactive gas of the inactive gas supply device 43b can be discharged into the chamber 3 from the discharge port 42 together with the ozone gas of the ozone gas generation device 42b (the same applies to fig. 8, 9, and 12 described later).

The gas discharge portion 5 is provided at a position spaced apart from the respective ejection ports 41 to 43 in the chamber 3 (a position on the side surface side of the chamber 3 in fig. 1), for example. The gas discharge unit 5 is configured to suck the gas in the chamber 3 and discharge the gas to the outside of the chamber 3, and is capable of maintaining the inside of the chamber 3 in a depressurized state (for example, a state in which the inside of the chamber 3 is in a vacuum environment). In the case of the gas discharge portion 5 of fig. 1, a configuration including an exhaust pipe 5a, a vacuum pump 5b, and the like is provided.

Film Forming Process Using ALD apparatus

In the ALD apparatus 11, a desired oxide film 21 can be formed on the film formation surface 20 of the object 2 to be formed in the chamber 3 by sequentially performing the source gas supply step S1, the source gas purge step S2, the oxidizing agent supply step S3, and the oxidizing agent purge step S4 shown in fig. 2.

In fig. 2, first, in a source gas supply step S1, a source gas (source gas including an element constituting the target oxide film 21) of a source gas supply device 41b is supplied from a discharge port 41 into the chamber 3. As a result, as shown in the reaction schematic diagram of fig. 3 (a), the source gas is adsorbed on the film formation surface 20 of the object 2 to be formed in the chamber 3, and an adsorption layer 21a based on the source gas is formed. Fig. 3 (a) depicts a state in which TMA gas of 1 molecular layer is adsorbed on the film formation surface 20 of the substrate-like film formation object 2.

When, for example, impurities or the like adhere to the film formation surface 20 of the object 2, it is preferable to clean the film formation surface 20 (for example, to supply the inert gas of the inert gas supply device 43b to the chamber 3 and purge) in the stage before the raw material gas supply step S1, so that the raw material gas is easily adsorbed to the film formation surface 20.

After the raw material gas supply step S1, in the raw material gas purge step S2, the inert gas of the inert gas supply device 43b is supplied from the discharge port 43 into the chamber 3, or the gas in the chamber 3 is sucked and discharged by the gas discharge portion 5. Thereby, the surplus gas of the source gas supplied in the source gas supply step S1 and the gas generated by the source gas being adsorbed on the film formation surface 20 are removed from the film formation surface 20.

Next, in the oxidizing agent supply step S3, ozone gas of the ozone gas generating device 42b is supplied from the discharge port 42 into the chamber 3. As a result, as shown in the reaction scheme of fig. 3 (b), the adsorption layer 21a formed on the film formation surface 20 is oxidized (methyl group (CH) is oxidized in fig. 3 ₃ ) Oxidation), an adsorbable region 20a for subsequent film formation is formed on the film formation surface 20. The oxidation reaction shown in the reaction scheme of FIG. 3 (b) can also be carried out at room temperature (25 ℃).

Then, in the oxidizing agent purging step S4, the inert gas of the inert gas supply device 43b is supplied from the discharge port 43 into the chamber 3, or the gas in the chamber 3 is sucked and discharged by the gas discharge portion 5, as in the raw material gas purging step S2. Thereby, the residual gas of the ozone gas supplied in the oxidizing agent supply step S3 and the gas generated by oxidizing the adsorption layer 21a of the raw material gas are removed from the film formation surface 20.

By appropriately repeating the above cycle (hereinafter simply referred to as a film formation cycle, as appropriate) in which the steps S1 to S4 are employed, the oxide film 21 having a desired thickness can be formed on the film formation surface 20. The various film formation conditions in the film formation cycle can be appropriately set, for example, in accordance with the target oxide film 21.

In the case of performing the above-described film formation cycle a plurality of times, for example, at least 1 step and the remaining steps in each source gas supply step S1 are each performed by supplying a different type of source gas to the object 2 to be formed, whereby the oxide film 21 having a multilayer structure including the adsorption layers 21a of different source gases (that is, the oxide film 21 formed by stacking the plurality of adsorption layers 21 a) can be formed.

< inert gas in Process S1 to S4 >

In the raw material gas purging step S2 and the oxidizing agent purging step S4, the inert gas of the inert gas supply device 43b is appropriately supplied into the chamber 3 while the gas in the chamber 3 is sucked by the gas discharge portion 5, so that the gas flow of the gas in the chamber 3 can be promoted, and the time required for removing (purging) the surplus gas and the like can be reduced.

The inert gas of the inert gas supply device 43b may be supplied appropriately in the raw gas supply step S1 and the oxidizing agent supply step S3.

For example, if the gas in the chamber 3 flows back to the gas supply unit 4, it is considered that the gas flowing back causes adhesion and film formation of particles in the gas supply unit 4 (the shower head 4a in example 3 described later), or the gas flow of the raw material gas and the ozone gas supplied from the gas supply unit 4 is blocked, and the inert gas is appropriately supplied as described above, whereby the back flow can be suppressed.

In addition, according to the volume, shape, etc. of the chamber 3 (for example, when the volume is large (for example, the volume exceeds 1 m) ³ In the case of complicated shape), the flow of the raw material gas and the ozone gas supplied from the gas supply unit 4 may be reduced, and the flow of the inert gas may be promoted by appropriately supplying the inert gas as described above (specifically, by adjusting the amount of the inert gas to be supplied or intermittently supplying the inert gas based on the volume and shape of the chamber 3).

Therefore, in each of the steps S1 to S4, the inert gas is appropriately supplied, so that the gas flow in the chamber 3 can be appropriately adjusted. This means that the raw material gas and ozone gas can be supplied in the desired amounts, or that the gas in the chamber 3 can be easily discharged.

< example of object 2 to be film-formed >

The object 2 to be formed may be appropriately subjected to a film formation cycle, and the desired oxide film 21 may be formed on the surface 20 to be formed, and examples thereof include various shapes such as a solid shape, a base plate shape, a powder shape (for example, an aggregate of a large number of particulate objects 2 to be formed), a film shape, a sheet shape, a cloth shape, and a fiber shape.

In addition, in the method of forming an oxide film using a source gas and an ozone gas having a high concentration of 80% by volume or more, the oxide film can be formed at a relatively low temperature, and therefore, for example, in the case of a substrate, a film or the like, the oxide film may be formed not only on a substrate or the like having relatively high heat resistance such as a Si substrate, but also on a substrate or the like formed of a synthetic resin having relatively low heat resistance.

When the object 2 to be formed is formed using a resin, examples of the resin include resins using a polyester resin, an aromatic polyamide resin, an olefin resin, polypropylene, PPS (polyphenylene sulfide), PET (polyethylene terephthalate), and the like.

Further, resins such as PE (polyethylene), PEN (polyethylene naphthalate), POM (polyoxymethylene, or acetal resin), PEEK (polyetheretherketone), ABS resin (acrylonitrile butadiene styrene copolymer synthetic resin), PA (polyamide), PFA (tetrafluoroethylene perfluoroalkoxyethylene copolymer), PI (polyimide), PVD (polyvinylidene chloride) and the like can be used.

The film formation surface 20 of the object 2 is not limited to be formed flat, and may be formed in various ways. For example, the object 2 shown in fig. 1 is a solid body having a plurality of fin-shaped protrusions formed thereon, and uneven steps are formed on the film formation surface 20.

For example, in the case where the object 2 to be film-formed is in a long film shape as in examples 3 and 4 described later, both or one of the front and back surfaces extending in the longitudinal direction may be flat film-forming surfaces 20.

The object 2 to be film-formed may be appropriately heated (for example, heated by a heating means such as a thermocouple or an infrared heater; not shown) for the purpose of improving film-forming performance. Specific examples thereof include heating as needed so that the film formation temperature of the film formation surface 20 is in the range of about room temperature to 100 ℃.

< one example of raw Material gas >

The source gas used In the source gas supply step S1 may include elements (e.g., lithium (Li), magnesium (Mg), silicon (Si), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), gallium (Ga), germanium (Ge), yttrium (Y), zirconium (Zr), molybdenum (Mo), ruthenium (Ru), rhodium (Rh), indium (In), tin (Sn), hafnium (Hf), tantalum (Ta), tungsten (W), iridium (Ir), platinum (Pt), lead (Pb), etc., and these elements are hereinafter referred to as metals or metal elements) as constituent elements.

Examples thereof include a raw material gas containing an organosilicon having a si—o bond or a si—c bond, an organometallic having a metal element-oxygen bond or a metal element-carbon bond, an organometallic complex, a raw material gas such as silicon or a metal hydride.

More specifically, examples of the source gas include silane (hydrogen silicide), TEOS (tetraethylorthosilicate), TMS (trimethoxysilane), TES (triethoxysilane), TMA (trimethylaluminum), TEMAZ (tetra (ethylmethylamino) zirconium), 3DAMAS (tris (dimethylamino) silane, siH [ N (CH) ₃ ) ₂ ] ₃ ) TDMAT (tetra (dimethylamino) titanium; ti [ N (CH) ₃ ) ₂ ] ₄ ) TDMAH (tetrakis (dimethylamino) hafnium; hf [ N (CH) ₃ ) ₂ ] ₄ ) And the like. Further, a raw material gas containing not more than 1 metal element but a heterogeneous compound of a plurality of metal elements (for example, a complex described in Japanese patent application laid-open No. 2016-210742) may be used.

In addition, for example, a carrier gas (N ₂ Ar, he, etc.) to supply (for example, supply at 1LSM or less) a source gas into the chamber 3. In the case of fig. 1, an inert gas of the inert gas supply device 43b may be used as a carrier gas.

< one example of ozone gas >

As for the ozone gas to be used in the oxidizing agent supply step S3, ozone gas of various concentrations can be used, and the higher the ozone concentration is, the more preferable is. Specifically, in the high concentration ozone gas, preferably to make the ozone concentration (volume% concentration) 80 ~ 100 volume%. Such high-concentration ozone gas can be obtained by liquefying and separating only ozone from ozone-containing gas based on the difference in vapor pressure, and then gasifying the liquefied ozone.

Examples of the ozone gas generating device 42b include those disclosed in patent documents of japanese patent application laid-open publication nos. 2001-304156 and 2003-20209. Such an ozone gas generating device 42b generates high-concentration ozone (ozone concentration: about 100 vol%) by liquefying and separating only ozone based on the difference in vapor pressure between ozone and other gases (e.g., oxygen). In particular, if a plurality of chambers are provided for liquefying and gasifying only ozone, the temperature of each of the chambers is controlled, whereby ozone gas having a high concentration can be continuously supplied.

The commercially available device for generating ozone gas of high concentration includes, for example, a pure ozone generator (MPOG-HM 1A 1) manufactured by Ministry of Bright and electric industries.

< one example of inactive gas >

The inert gas may be used in, for example, the raw material gas purging step S2 and the oxidizing agent purging step S4. As an example thereof, N ₂ Inert gases such as Ar and He.

< one example of the gas supply portion 4 >

The gas supply unit 4 may have the discharge ports 41 to 43, and may supply the source gas, ozone gas, and inert gas to the chamber 3 at a desired supply amount (flow rate, etc.), pressure, etc., for example, and various means may be applied.

The number of the ejection ports 41 to 43 may be not only 1 for each chamber 3 but also plural. The shape of the ejection ports 41 to 43 may be appropriately set, and examples thereof include circular, rectangular, elliptical, slit-shaped, and the like.

The supply amounts and pressures of the gases supplied from the discharge ports 41 to 43 can be appropriately set by providing, for example, flow rate variable valves and the like outside the drawing in the pipes 41a to 43 a.

< one example of gas supply amount, pressure, etc. >)

The amounts of the source gas, the ozone gas, the inert gas, and the like supplied to the chamber 3, the pressures generated by the gases (for example, the pressures (partial pressures) generated by the ozone gas in the chamber 3) and the like are appropriately controlled and set in the embodiment 3 described later, for example, the pressures between the ejection ports 41 to 43 and the like and the film formation surface 20, and examples thereof include the types, shapes, numbers, the types, the concentrations, and the like of the film formation object 2 in the chamber 3.

As a specific example, in the case of performing the film formation cycle using the respective steps S1 to S4 as shown in fig. 4, there may be mentioned a case where the supply amount of each gas is appropriately set so that the process pressure in the chamber 3 generated in the film formation cycle falls within a range of 1000Pa or less. More specifically, the inert gas is supplied from the inert gas outlet 43 into the chamber 3 (for example, intermittently supplied as described later), and the basic pressure is appropriately controlled and set so as to fall within a range of about 1Pa to 1000Pa by the supply. The time required for 1 film formation cycle can be appropriately set, and is not particularly limited, and examples thereof include a time set to several seconds to several tens of seconds (for example, 3 seconds to 60 seconds).

In the case where 80% by volume or more of the ozone gas is supplied to the chamber 3 in the oxidizing agent supplying step S3, the exposure amount of the ozone gas to the film formation surface 20 may be 1×10 ⁵ The supply amount of the ozone gas is appropriately set so that the pressure of the ozone gas generated in the chamber 3 becomes 100Pa or less.

For example, when an inert gas is present in the chamber 3 in addition to ozone gas, the partial pressure of the ozone gas is set to 100Pa or less. The pressure rise due to the supply of ozone gas is appropriately set to 100Pa or less, preferably 50Pa or less, and more preferably 10Pa or less.

According to the oxidizing agent supply step S3, the adsorption layer 21a adsorbed on the film formation surface 20 in the raw material gas supply step S1 can be sufficiently oxidized.

The amount of the source gas supplied to the chamber 3 in the source gas supply step S1 and the like may be set so that the source gas is adsorbed on the film formation surface 20 and sufficiently oxidized (oxide film is formed) in the subsequent oxidizing agent supply step S3, for example.

Specific examples thereof include a film formation surface 20 having an exposure of 1×10 to a raw material gas ⁴ The supply amount of the source gas and the like are appropriately set so as to be equal to or larger than langmuir. In addition, the exposure amount of the raw material gas varies according to the adsorption rate of the raw material gas. Therefore, for example, even if the source gases are different in type, when the adsorption rate to the film formation surface 20 is the same, it is considered that the supply amounts of the source gases are set to the same level. As an example of the raw material gas having the same adsorption rate, TMA, TDMAT, TDMAH and the like are given.

In the raw material gas purging step S2 and the oxidizing agent purging step S4, the amount of the inert gas to be supplied to the chamber 3 and the like may be appropriately set as long as the process pressure is within the range of 1000Pa or less as described above. For example, in the case of purging by the gas discharge portion 5, the purging may be set to a degree that can assist the purging. Specific examples thereof include intermittent supply of an inert gas to the chamber 3, and appropriate setting of the inert gas and the ozone gas (for example, setting to 10 times or less the amount of ozone gas supplied) so as to excessively dilute the raw material gas and the ozone gas in the chamber 3.

< one example of the gas discharge portion 5 >

The exhaust gas passing through the gas discharge portion 5 is not particularly limited as long as the reduced pressure state in the chamber 3 can be maintained so that the process pressure in the chamber 3 is within a range of 1000Pa or less as described above.

In the case of the gas discharge portion 5 of fig. 1, the configuration of having the exhaust pipe 5a, the vacuum pump 5b, and the like may be adopted, and the configuration of appropriately having an ozone eliminator (a pest elimination device such as a pest elimination tube for decomposing ozone; not shown), an exhaust valve (a valve for adjusting the opening degree; not shown), and the like may be adopted. The vacuum pump 5b is preferably configured to have resistance to ozone (for example, a dry pump).

In addition, a plurality of exhaust pipes may be provided in the gas discharge portion 5, and the exhaust pipes may be used separately in the respective steps S1 to S4. In this way, the exhaust gas can be distributed to the dedicated pest control devices and treated in each of the steps S1 to S4.

< one example of supporting portion >

The support portion for supporting the object 2 accommodated in the chamber 3 is not particularly limited as long as it can support the object so as not to interfere with the film formation on the film formation surface 20. Specific examples include those shown in examples 2 to 4 described below.

Film formation Using ALD apparatus 11

Based on example 1 shown above, a film formation cycle using the ALD apparatus 11 was appropriately performed to form Al on the film formation surface 20 of the object 2 to be formed ₂ O ₃ The oxide film 21 of (a) was verified, and the results shown in fig. 5 to 7 were obtained.

As the verification conditions, TMA was applied as the source gas supplied in the source gas supply step S1 to raise the pressure of the ozone gas (concentration 80 to 100 vol%) supplied in the oxidizing agent supply step S3 to 50Pa, and the exposure time of the ozone gas was 3 seconds or less. In addition, the object 2 to be film-formed is formed by PEN in the film formation shown in fig. 5 and 6, and is formed by Si substrate in the film formation shown in fig. 7. The film formation temperature was set so as to be about room temperature.

Fig. 5 shows film thickness characteristics of the oxide film 21 when film formation cycles are performed at various film formation temperatures. According to FIG. 5, GPC (growth per cycle) was read as 1.7/cycle at a film formation temperature of about room temperature (25 ℃). As a comparative example, the oxide film 21 was formed at a relatively high film formation temperature by the conventional ALD method, and as a result, GPC was about 1.0 to 1.2 per cycle. Therefore, according to example 1, it was confirmed that a good film formation rate characteristic was obtained as compared with the conventional ALD method.

Fig. 6 shows the water vapor permeability characteristics of the object 2 with respect to the elapsed time, in a case where the oxide film 21 having a film thickness of 40nm is formed on the film formation surface 20 on one end side in the film thickness direction of the object 2. According to this FIG. 6, the reading is performedThe water vapor permeability converged to 4.4X10 as time passed ^-4 g/m ² About/day. The water vapor permeability of the object 2 to be film-formed before forming the oxide film 21 was measured, and found to be 10 ^-1 g/m ² About/day. Therefore, according to example 1, it was confirmed that good barrier properties were obtained in the oxide film 21.

Fig. 7 shows leakage current density characteristics with respect to the applied electric field strength in the oxide film 21. From this FIG. 7, it was found that the dielectric breakdown strength of 10MV/cm or more was obtained in the oxide film 21. Therefore, according to example 1, it was confirmed that leakage current was sufficiently suppressed in the oxide film 21, and good insulation was obtained.

In the verification, the exposure of the ozone gas to the film formation surface 20 was confirmed to reach 1.1X10 th ⁶ About Lang Miao Erzuo (i.e. over 1X 10) ⁵ Degree of langmuir 1 digit).

Example 2

In example 2, a plurality of objects 2 to be formed, for example, a large number of aggregates (hereinafter simply referred to as "object aggregate" as appropriate) 22 of the objects 2 to be formed in a particle form as shown in fig. 8 b described later, can be accommodated and supported, and oxide films 21 can be simultaneously formed on the surfaces 20 to be formed of the objects 2 to be formed.

< principal constituent of ALD apparatus 12 >

Fig. 8 illustrates an ALD method based on example 2, showing a schematic of an ALD apparatus 12 applicable in this example 2. The ALD apparatus 12 of fig. 8 includes a support portion 6 having a housing-shaped housing wall 61 that can be disposed in the chamber 3, and is configured to house and support a plurality of objects 2 to be formed in the housing wall 61.

The housing wall 61 is configured to removably house a plurality of objects 2 to be film-formed. Further, at least a part of the housing wall 61 is provided with a ventilation portion 62 having a plurality of ventilation holes with a smaller diameter than the maximum outer diameter (particle diameter or the like) of the object 2 to be film-formed. In the case of the housing wall 61 of fig. 8, the housing wall has a cylindrical configuration, and ventilation portions 62 are provided at positions on both end sides in the axial direction.

As described above, the support portion 6 may be configured to hold a plurality of objects 2 to be formed and form the oxide film 21 on the film formation surface 20, and various configurations may be applied.

For example, the housing wall 61 is configured to be rotatable (for example, rotatable about an axis in the case of the housing wall 61 of fig. 8), so that the object 2 to be film-formed in the housing wall 61 can be formed while being stirred. This can suppress and prevent uneven formation of an oxide film on the object to be formed.

In the ventilation unit 62, the gas (raw material gas, ozone gas, inert gas, etc.) in the chamber 3 may pass through, and may block the passage of the object to be film-formed, and various means may be applied. As an example thereof, there may be mentioned a ventilation portion having a mesh structure having a plurality of ventilation holes smaller than the particle size of each object 2 to be film-formed of the aggregate 22.

Film formation Using ALD apparatus 12

Based on example 2 shown above, the film formation cycle using the ALD apparatus 12 was appropriately performed, and Al was formed on the film formation surface 20 of the aggregate 22 of a large number of particle-shaped film formation objects 2 ₂ O ₃ And verified. The verification conditions were the same as those in example 1, and the object 2 having a particle diameter of 1mm or less was used as the object.

As a result, it was confirmed that good film formation rate characteristics, barrier properties, and insulation properties were obtained in the oxide film 21 in the same manner as in example 1.

Example 3

In example 3, the object 2 to be film-formed can be moved (moved in one of the two directions or reciprocated in the two directions) in two opposite directions (hereinafter simply referred to as the two directions of the film-forming surface as appropriate) along the four directions of the film-forming surface 20, and the oxide film 21 can be formed on the film-forming surface 20.

< principal constitution of ALD apparatus 13 >

Fig. 9 illustrates an ALD method according to example 3, showing a schematic of an ALD apparatus 13 applicable in this example 3. The ALD apparatus 13 of fig. 9 is constructed in the following manner: the object 2 to be deposited accommodated in the chamber 3 can be supported by the support portion 7 provided in the chamber 3 so as to be movable in two opposite directions along the longitudinal direction of the surface 20 to be deposited (in the following, simply referred to as "two directions of the surface to be deposited" as appropriate).

The support portion 7 of fig. 9 is constituted as follows: the so-called roll-to-roll system includes one end side roller 71 which is a spool that winds one end side of the long film-shaped object 2, the other end side roller 72 which is a spool that winds the other end side of the object 2, and conveying rollers 73a and 73b disposed between the one end side roller 71 and the other end side roller 72, and the rollers are rotated appropriately.

By the support 7, the film formation object 2 fed out by one of the one end side roller 71 and the other end side roller 72 is wound around the other via the conveying rollers 73a and 73 b. That is, according to the support portion 7, the object 2 to be film-formed can be appropriately moved in both directions of the film-forming surface. In the case of the support 7 in fig. 9, the conveying rollers 73a and 73b are disposed at a predetermined interval above the chamber 3 so that the film formation surface 20 of the object 2 to be formed moving between the rollers faces the upper side of the chamber 3 (faces a shower head 4a described later).

A gas supply portion 4 having a shower head 4a is provided above the chamber 3. The shower head 4a has a configuration having a plurality of discharge ports 41 to 43, and is provided at a position facing the film formation surface 20 of the film formation object 2 moving between the conveying rollers 73a and 73 b.

The discharge ports 41 to 43 of the shower head 4a are connected to a source gas supply device 41b, an ozone gas generation device 42b, and an inert gas supply device 43b via pipes 41a, 42a, and 43a, respectively. This allows the gas from each of the devices 41b to 43b to be appropriately supplied from the discharge ports 41 to 43 into the chamber 3.

< another example of the supporting portion 7 >

The support portion 7 is not limited to the roll-to-roll type shown in fig. 9, as long as it can support the object 2 accommodated in the chamber 3 movably in both directions of the film formation surface. For example, there is a configuration in which a support table (hereinafter simply referred to as a support table method as appropriate) for supporting the object 2 to be formed (for example, a support table shown by reference numeral 7 in fig. 1 of japanese patent No. 6052470) is provided, and the support table is allowed to move in both directions of the surface to be formed (the surface 20 to be formed is allowed to move freely so as to face the shower head 4 a).

< one example of the showerhead 4a >

Fig. 10 shows an example of the shower head 4 a. In fig. 10 (and fig. 11 described later), solid arrows without reference numerals indicate one example of the supply direction of each gas, and broken arrows indicate one example of the exhaust direction of each gas.

In the shower head 4a of fig. 10, a plurality of ejection ports 41 and 42 are provided at a portion 4b facing the film formation surface 20 of the object 2 to be formed moving between the conveying rollers 73a and 73b, respectively.

The ejection ports 41 and 42 are alternately located at predetermined intervals in both directions of the film formation surface, and pairs of ejection ports 41 and 42 adjacent to each other (for example, pairs of ejection ports indicated by reference symbol T in fig. 10) are arranged at predetermined intervals in both directions of the film formation surface.

Further, a discharge port 43 is provided between both the discharge ports 41 and 42. Further, an inter-discharge port exhaust port 44 is provided between the discharge ports 41 to 43. The exhaust port 44 is configured to be capable of sucking gas or the like between the exhaust port 44 and the film formation surface 20 and discharging the gas or the like to the outside of the chamber 3.

< example of the ejection ports 41 to 43 and the exhaust port 44 in the showerhead 4a >

The plurality of the discharge ports 41 to 43 and the discharge port 44 (hereinafter simply referred to as discharge ports, as appropriate) in the shower head 4a may be arranged in a plurality of rows along only two directions of the film formation surface, but may be arranged in a plurality of rows in a crossing direction (hereinafter simply referred to as crossing direction, as appropriate) crossing the two directions of the film formation surface. Examples include: the plurality of the discharge ports 41 are arranged in the intersecting direction to constitute a raw material gas discharge port group, or the plurality of the discharge ports 42 are arranged in the intersecting direction to constitute an ozone gas discharge port group.

The configuration (shape, size, etc.) of the ejection port, etc. and the distance from the film formation surface 20 of the object 2 are not limited to the same, but may be different from each other.

Examples include: as shown in fig. 11, the dimensions V1 to V8 of the film formation surface of the ejection port or the like in both directions (slit width in the case of the long slit-shaped ejection port or the like in the intersecting direction) are set to 10 ^-1 In the range of mm to hundreds of mm, preferably in the range of 1mm to 100 mm. In addition, there may be mentioned: the distance h1 to h8 between each of the ejection ports and the like and the film formation surface 20 of the object 2 to be formed is set to be in the range of several mm to several hundred mm, preferably in the range of 1mm to 100mm, and more preferably (particularly, the ejection port 42) in the range of 1mm to 20 mm. In the case of figure 11 of the drawings, the distance h8 of the ejection port 42 is set to be larger than the distances h1 to h7 of the other ejection ports and the like.

The pitch (W1 to W8 in fig. 11) between the ejection ports and the like is appropriately set in consideration of the opening sizes of the ejection ports and the like, for example.

< example of object 2 to be film-formed >

The object 2 to be formed is not particularly limited as long as it is supported movably by the support portion 7 (for example, supported by a roll-to-roll system or a support table system), and the oxide film 21 can be formed on the surface 20 to be formed while the object 2 to be formed is moved in both directions of the surface to be formed.

In the case of the object 2 shown in fig. 9, the front and rear surfaces of the long film shape extending in the longitudinal direction are the film formation surfaces 20 (one of the front and rear surfaces is the film formation surface 20 in fig. 9), and are supported by the support portions 7 so as to be movable in the longitudinal direction (both directions of the film formation surfaces).

< gas supply amount, pressure, etc. >)

The flow rates (supply amounts) of the source gas, ozone gas, inert gas, and the like supplied from the outlets 41 to 43 in the shower head 4a to the chamber 3, the pressures generated by the respective gases, and the like can be appropriately set in the same manner as in examples 1 and 2, and examples thereof include a distance between the outlets and the like, a moving speed of the object 2 to be film-formed in both directions of the film-forming surface, an exhaust speed of the outlets and the like (a pressure of the film-forming portion), and the like.

By setting the movement speed of the object 2 to be formed in two directions on the surface to be formed, and the like, as described above, the exposure amount of the ozone gas to the surface 20 to be formed can be set to 1×10, for example ⁵ The pressure of the ozone gas is set to 100Pa or lower and the exposure amount of the source gas to the film formation surface 20 is set to 1×10 ⁴ Langmuir above. As a result, the adsorption layer 21a adsorbed on the film formation surface 20 in the raw material gas supply step S1 can be sufficiently oxidized in the oxidizing agent supply step S3.

As a specific example, the flow rate of the ozone gas may be 0.1sccm to 10sccm per unit length in a direction perpendicular to both directions of the film formation surface, which is provided as the discharge port 42.

The flow rate of the source gas may be 0.0001sccm to 1sccm per unit length in a direction perpendicular to the two directions of the surface to be formed, which is defined as the ejection port 41.

The flow rate of the inert gas may be set relatively large in a range where the process pressure does not exceed 1000Pa (for example, set to be larger than the ozone gas flow rate).

The moving speed of the object 2 to be film-formed in both directions of the film-forming surface may be appropriately set in consideration of the intervals between the ejection ports and the like. By the magnitude of the movement speed and the like set in this way, convection occurs between each ejection port and the like and the surface 20 to be formed, and for example, the reaction of each gas with respect to the surface 20 to be formed may be promoted, and film formation easiness and the like may be facilitated.

< example of film Forming Process when Using ALD apparatus 13 >

When film formation is performed by the ALD apparatus 13, for example, the film formation cycle is appropriately performed while moving the object 2 to be film-formed in both directions on the film formation surface by moving the object 2 to be film-formed supported by the support portion 7 from the one end side roller 71 to the other end side roller 72 (moving from the left side to the right side in the drawing in fig. 9).

In this case, for example, as shown in fig. 10, the film formation surface 20 sequentially passes through the regions A1 to A4, and the respective steps S1 to S4 are performed in the regions A1 to A4 as follows.

First, in the region A1, the source gas is discharged from the discharge port 41 in the source gas supply step S1. As a result, as shown in the reaction scheme in fig. 3 (a), the source gas is adsorbed on the film formation surface 20, and an adsorption layer 21a is formed from the source gas.

After the source gas supply step S1 in the region A1, the surplus gas of the source gas supplied in the step S1 and the gas (CH ₄ Gas) is removed through the exhaust port 44 and the gas exhaust unit 5, or through the raw material gas purging step S2. In the raw material gas purging step S2, inert gas is discharged from the discharge port 43, and the surplus gas or the like is removed from the region A1.

Next, in the region A2, ozone gas is injected from the injection port 42 in the oxidizing agent supply step S3. As a result, as shown in the reaction scheme of fig. 3 (b), the adsorption layer 21a generated from the source gas adsorbed on the film formation surface 20 oxidizes, thereby forming an oxide film 21. Then, on the surface of the oxide film 21, an adsorbable region 20a for the subsequent film formation is formed.

After the oxidizing agent supply step S3 in the region A2, the surplus gas of the ozone gas supplied in the step S3 and the gas generated by oxidizing the adsorption layer 21a are removed through the inter-outlet exhaust port 44 and the gas discharge portion 5, or through the oxidizing agent purge step S4. In the oxidizing agent purging step S4, inert gas is discharged from the inert gas discharge port 43, and the surplus gas or the like is removed from the region A2.

The film formation cycle of each of the steps S1 to S4 in the regions A1 and A2 shown above is similarly performed in the region (for example, the regions A3 and A4 in fig. 10) subsequent to the regions A1 and A2.

It is found that the desired oxide film 21 can be formed on the film formation surface 20 by appropriately performing the film formation cycle as described above. Further, by performing a plurality of film formation cycles, a desired film thickness can be formed on the oxide film 21.

As a method of performing the multiple film formation cycles, for example, a method of moving the object 2 to be formed in one direction or a method of reciprocating in two directions on the film formation surface, thereby performing the film formation cycles of the multiple regions A1 to A4 appropriately is exemplified.

Film formation Using ALD apparatus 13 >

Based on example 3 shown above, the film formation cycle using the ALD apparatus 13 was appropriately performed, and Al was formed on the film formation surface 20 of the long film-like object 2 ₂ O ₃ And verified. In addition, PEN film formation was applied to the object 2 to be film-formed under the same verification conditions as in example 1.

As a result, in the same manner as in example 1, except that good film formation rate characteristics and barrier properties were obtained in the oxide film 21 (the water vapor permeability was 4.0X10 in example 3) ^-4 g/m ² About/day), and the insulation properties, the following can be confirmed.

That is, according to example 3, the respective steps S1 to S4 of the film formation cycle can be performed appropriately at the same time while moving the object 2 to be formed in both directions on the film formation surface, and therefore, the film formation time can be easily shortened as compared with examples 1 and 2.

Further, since the inert gas outlet 43 and the inter-outlet exhaust port 44 are provided between the raw material gas outlet 41 and the ozone gas outlet 42, for example, dispersion of the raw material gas and the ozone gas in the chamber 3 can be suppressed. This can suppress adhesion and film formation of particles generated by the source gas and ozone gas on the inner wall surface of the chamber 3, for example, and can reduce the burden on maintenance of the chamber 3 (cleaning process in the chamber 3, etc.).

Example 4

In example 4, the roll-to-roll system shown in example 3 was applied to divide the chamber 3 into a plurality of gas processing furnaces so that the respective steps S1 to S4 of the film formation cycle could be appropriately divided into the respective gas processing furnaces.

< principal constituent of ALD apparatus 14 >

Fig. 12 illustrates an ALD method according to example 4, showing a schematic of an ALD device 14 applicable in this example 4. The ALD apparatus 14 of fig. 12 includes a chamber 30 having a divided structure and a support portion 8, and is configured to be capable of movably supporting the long film-shaped object 2 to be formed in two directions of the film-forming surface by using the support portion 8.

The chamber 30 has: a raw material gas treatment furnace 31 provided with a raw material gas discharge port 41, an ozone gas treatment furnace 32 provided with an ozone gas discharge port 42, and an inert gas treatment furnace 33 provided with an inert gas discharge port 43 interposed between the raw material gas treatment furnace 31 and the ozone gas treatment furnace 32.

In the case of the chamber 30 of fig. 12, an inert gas treatment furnace 34 having the same structure as that of the inert gas treatment furnace 33 is provided at a position opposite to the inert gas treatment furnace 33 sandwiching the raw material gas treatment furnace 31. The inert gas treatment furnace 34 can be used to clean the film formation surface 20 between, for example, one end side roller 71, the other end side roller 72, and the raw material gas treatment furnace 31, which will be described later, and may be omitted as appropriate.

The furnace walls of the processing furnaces 31 to 34 are provided with processing furnace openings 31a to 34a through which the object 2 to be film-formed can pass, respectively, at positions intersecting with the movement path of the object 2 to be film-formed in the wall. The process furnace openings 31a to 34a are each configured to allow the film formation object 2 to pass therethrough without interfering with the reduced pressure state in the process furnaces 31 to 34 (for example, a configuration using a parallel seal slit valve or the like for a vacuum chamber).

The support portion 8 is constituted as follows: the so-called roll-to-roll system includes one end side roller 71 which is a reel around which one end side of the object 2 to be formed is wound, the other end side roller 72 which is a reel around which the other end side of the object 2 to be formed is wound, the 1 st return roller 74 disposed in the raw material gas treatment furnace 31, and the 2 nd return roller 75 disposed in the ozone gas treatment furnace 32, and the rollers are rotated appropriately.

In the case of the support portion 8 of fig. 12, the one end side roller 71 and the other end side roller 72 are provided on the outer peripheral side of the chamber 30 so as to be located on the opposite side of the inert gas treatment furnace 33 with respect to the raw material gas treatment furnace 31 (and the inert gas treatment furnace 34).

The 1 st folding roller 74 and the 2 nd folding roller 75 support the film formation object 2 between the one end side roller 71 and the other end side roller 72 so as to fold back at the respective positions (in the respective processing furnaces 31, 32).

As a result, the object 2 to be film-formed between the one end side roller 71 and the other end side roller 72 is supported by being extended so as to be bent back and forth and overlapped at two places in the raw material gas treatment furnace 31 and the ozone gas treatment furnace 32, as depicted in fig. 12, for example. Each time the raw material gas treatment furnace 31 and the ozone gas treatment furnace 32 move between them (hereinafter simply referred to as "movement between them" as appropriate), the raw material gas treatment furnace passes through the inactive gas treatment furnace 33.

The 1 st folding roller 74 and the 2 nd folding roller 75 are arranged in plural in the overlapping direction of the film formation object 2. By appropriately changing the number of rows, the number of movements between the two objects 2 to be film-formed can be set as desired.

In the ALD apparatus 14, the same pipes 41a to 43a, the same apparatuses 41b to 43b, and the like as in the ALD apparatuses 11 to 13 are connected to the respective ejection ports 41 to 43, respectively, but the description thereof is omitted in fig. 12 as appropriate. The process furnaces 31 to 34 are provided with the gas discharge units 5 similar to the ALD apparatuses 11 to 13, and the reduced pressure state in the process furnaces 31 to 34 can be maintained, respectively, but the description thereof is omitted in fig. 12 as appropriate.

< one example of a film Forming Process when the ALD apparatus 14 is used >

When film formation is performed by the ALD apparatus 14, first, the object 2 to be film-formed supported by the support portion 8 is moved from the one end roller 71 to the other end roller 72. Then, each time the object 2 moves between the two objects to be film-formed and reciprocates, the film-forming cycle of each of steps S1 to S4 is performed.

By appropriately performing such a film formation cycle, a desired oxide film 21 can be formed on the film formation surface 20. As a method of performing the film formation cycle a plurality of times, for example, a method of moving the object 2 to be formed in one direction or a method of reciprocating in two directions on the surface to be formed, thereby performing the film formation cycle a plurality of times appropriately is exemplified.

< gas supply amount, pressure, etc. >)

The amounts of the source gas, ozone gas, inert gas supplied from the outlets 41 to 43 (the amounts of filling) and the pressure generated by the gases may be appropriately set in the same manner as in examples 1 and 2, and examples thereof include the moving speed of the object 2 to be formed in both directions on the film formation surface.

According to the chamber 30 having the structure of the plurality of processing furnaces 31 to 34 as in example 4, the raw material gas, the ozone gas, and the inert gas (for example, the raw material gas, the ozone gas, and the inert gas are supplied to the different processing furnaces 31 to 34) can be appropriately supplied to the processing furnaces 31 to 34 and filled, and after this filling, the processing furnaces 31 to 34 are not mixed with each other.

Therefore, for example, if the oxide film 21 is formed in a state that can be facilitated by supplying and filling a predetermined amount of the source gas and the ozone gas to the processing furnaces 31 and 32, respectively (the exposure amounts of the source gas and the ozone gas to the film formation surface 20 are 1×10, respectively) ⁵ Langmuir or more, 1×10 ⁴ Langmuir or more), new additions or replacement are not necessary. For example, if the ozone gas with a high concentration is in the range of about room temperature to 400 ℃, the thermal decomposition reaction due to collision between ozone or the like can be suppressed, and a contribution can be made to the formation of the oxide film 21 for a sufficiently long time.

Accordingly, the gases to be charged into the process furnaces 31 to 34 can be replaced periodically (for example, every 1 hour) without being supplied constantly.

In the case where the raw material gas and the ozone gas are supplied to the processing furnaces 31 and 32, respectively, the inert gas may be supplied appropriately to the chamber 30. Thus, it is known that the flow of the gas in the process furnaces 31 and 32 can be appropriately adjusted, and the raw material gas and the ozone gas can be supplied in desired supply amounts, or can be easily diffused in the process furnaces 31 and 32, or the gas in the process furnaces 31 and 32 can be easily discharged.

In addition, the pressure of each of the treatment furnaces 31 to 34 may be different from each other. For example, the pressure of the process furnaces 31 and 32 is set in a range where gas leakage from the process furnaces 31 and 32 does not occur. On the other hand, in the case of the process furnaces 33 and 34, the inert gas in the process furnaces 33 and 34 is safer (safer than the source gas and ozone gas) even if it leaks, and therefore, can be set higher than the process furnaces 31 and 32.

The moving speed of the object 2 to be film-formed in both directions on the film-forming surface may be appropriately set in consideration of the concentration, pressure, and the like of each gas in the chamber 30. The convection current may be generated in the film formation surface 20 depending on the magnitude of the movement speed and the like set in this way, for example, the reaction of each gas with respect to the film formation surface 20 may be promoted, and the film formation may be facilitated.

Specific examples thereof include setting the passage time (residence time) of the treatment furnaces 31, 32 to 0.1 seconds or more and 1 second or more, respectively, each time the object 2 to be film-formed moves between them.

< 1 st turning roller 74, 2 nd turning roller 75 example >

The shape, arrangement, and the like of the 1 st folding roller 74 and the 2 nd folding roller 75 can be appropriately set, and are not particularly limited.

If the number of the 1 st turning-back roller 74 and the 2 nd turning-back roller 75 is increased, for example, it is considered that the film formation object 2 in the chamber 30 of the ALD apparatus 14 is increased in size in the overlapping direction (hereinafter, simply referred to as the overlapping direction as appropriate) or the supply amount of the gas to the chamber 30 is increased. Further, it is also considered that the formation area of the process furnace openings 31a to 33a is enlarged or the penetration angle of the film formation object 2 into the process furnace openings 31a to 33a is increased, and that gas leakage occurs when a gap is generated between the process furnace openings 31a to 33a and the film formation object 2.

In this case, for example, there may be mentioned: as shown in fig. 12, in the path of the meandering object 2, a position adjustment roller 76 is provided between the 1 st folding roller 74 and the processing furnace opening 31a in the processing furnace 31 at a position facing the processing furnace opening 31 a. In addition, there may be mentioned: in the process furnace 32, similarly, a position adjustment roller 77 is provided between the 2 nd folding roller 75 and the process furnace opening 32a at a position facing the process furnace opening 32 a.

In the case of the position adjustment rollers 76, 77 in fig. 12, the arrangement dimensions in the overlapping direction are narrower than the arrangement dimensions in the overlapping direction of the 1 st and 2 nd folding rollers 74, 75. Thereby, the meandering object 2 is supported so as to converge in the overlapping direction.

By disposing the position adjustment rollers 76 and 77 as described above, the ALD apparatus 14 can be miniaturized and the supply amount of each gas can be reduced. In addition, the penetration angle of the object 2 into the process furnace openings 31a to 33a can be reduced, and the gas leakage can be suppressed.

Film formation Using ALD apparatus 14

Based on example 4 described above, a film formation cycle by the ALD apparatus 14 was appropriately performed, and an attempt was made to form Al on the film formation surface 20 of the long film formation object 2 ₂ O ₃ Is formed on the substrate. In addition, the verification conditions were the same as in example 1, and PEN film formation was applied to the object 2 to be film-formed.

As a result, in the same manner as in example 1, good film formation rate characteristics and barrier properties were obtained in the oxide film 21 (water vapor permeability of 4.0X10 in example 4) ^-4 g/m ² About day), and further, as in example 3, it is possible to easily shorten the film formation time or to reduce the burden involved in maintenance, and it is also possible to confirm the following.

That is, in example 4, since the gases filled in the process furnaces 31 to 34 of the chamber 30 do not need to be replaced frequently, the gases can be used more efficiently (the supply amount is reduced) than in example 3.

The ALD method of the present invention has been described above by showing specific embodiments, but is not limited to this embodiment, and can be appropriately modified in design within a range that does not impair the characteristics thereof, and the modification in design also falls within the technical scope of the present invention.

For example, by performing a CVD process before and after the film formation process by the ALD method of the present embodiment, a film having a multilayer structure of an ALD film and a CVD film can be formed on the film formation surface 20 of the same object 2 to be formed. For example, if CVD is to be used, siO with high film formation speed and high elastic endurance ₂ The film was CVD-formed on SiO ₂ Al having high water vapor permeability between films ₂ O ₃ When the film is ALD-formed, a film having a multi-layer structure with a multi-functionality that cannot be realized by a single layer film can be formed at a low temperature.

The respective components of the ALD apparatuses 11 to 14 may be omitted as appropriate insofar as the desired oxide film 21 can be formed on the film formation surface 20. For example, when the raw material gas purging step S2, the oxidizing agent purging step S4, and the like can be sufficiently achieved by the gas suction in the chamber 3 using the gas discharge portion 5, the inert gas discharge port 43 and the like can be appropriately omitted. In the case of the ALD apparatus 13, the inter-orifice exhaust port 44 and the like may be omitted appropriately (for example, the inter-orifice exhaust port and the like are provided only in a part of each of the inter-orifice exhaust ports).

Claims (20)

1. An atomic layer deposition method for forming an oxide film on a film formation object in a chamber of an atomic layer deposition apparatus, comprising:

a source gas supply step of supplying a source gas containing an element constituting an oxide film into the chamber, and forming an adsorption layer of the source gas on a film formation surface;

a source gas purging step of removing, from the film formation surface, the surplus gas of the source gas supplied in the source gas supplying step and the gas generated by the adsorption of the source gas on the film formation surface;

An oxidizing agent supply step of supplying 80% by volume or more of ozone gas into the chamber to oxidize the adsorption layer formed on the film formation surface; and

an oxidizing agent purging step of removing the residual gas of the ozone gas supplied in the oxidizing agent supplying step and the gas generated by oxidizing the adsorption layer of the raw material gas from the surface to be formed,

in the oxidant supply step, the exposure of the ozone gas to the film-forming surface is set to 1X 10 ⁵ Langmuir or more, the pressure in the chamber is set to 1000Pa or less.

2. The atomic layer deposition method according to claim 1, wherein the atomic layer deposition apparatus includes:

a chamber capable of freely accommodating the object to be formed,

A support part for supporting the object to be formed,

A gas supply part for supplying gas into the chamber,

A gas discharge part for sucking gas in the chamber and discharging the gas to the outside of the chamber to maintain the reduced pressure state in the chamber,

the gas supply unit has:

a raw material gas outlet for discharging raw material gas into the chamber,

Ozone gas discharge port for discharging ozone gas into chamber, and method for manufacturing the same

An inert gas ejection port for ejecting inert gas into the chamber.

3. The atomic layer deposition method according to claim 1 or 2, wherein each of the processes adjusts a gas flow in the chamber by supplying an inert gas into the chamber.

4. The atomic layer deposition method according to claim 3, wherein the supply amount of the inert gas is adjusted based on a volume or a shape in the chamber.

5. The atomic layer deposition method according to any one of claims 2 to 4, wherein the support portion has a housing-shaped housing wall capable of being placed in the chamber and capable of housing a plurality of objects to be deposited in a removable manner,

at least a part of the housing wall is provided with a ventilation part through which the gas in the chamber can pass and which blocks the passage of the object to be film-formed.

6. The atomic layer deposition method according to any one of claims 2 to 4, wherein the support portion supports the object to be film-formed in two directions opposite to each other in four directions along the surface to be film-formed,

the gas supply part is provided with a spray head which is arranged in the chamber and is opposite to the film forming surface of the film forming object,

in the case of a shower head, the shower head,

the raw material gas ejection port and the ozone gas ejection port are provided alternately opposite to the film formation surface of the film formation object with a predetermined interval therebetween in the two directions,

an inert gas outlet is provided between the raw material gas outlet and the ozone gas outlet,

each of the steps is performed on the film formation surface according to the movement of the film formation object in the two directions.

7. The atomic layer deposition method according to claim 6, wherein an inter-ejection port exhaust port is provided at least any one of the respective ejection port intervals of the showerhead.

8. The atomic layer deposition method according to claim 6 or 7, wherein the support portion has: one end side roller for winding and supporting one end side of the object to be formed and the other end side roller for winding and supporting the other end side of the object to be formed are supported in a free manner by a roll-to-roll manner.

9. The atomic layer deposition method according to claim 6 or 7, wherein the support portion has a support table for supporting the object to be film-formed, and the support table is allowed to move freely along the film-forming surface of the object to be film-formed.

10. The atomic layer deposition method according to any one of claims 6 to 9, wherein pairs of ejection orifices of the shower head, which are composed of a raw material gas ejection orifice and an ozone gas ejection orifice that are adjacent to each other, are arranged in plurality at a given interval in the two directions.

11. The atomic layer deposition method according to any one of claims 6 to 10, wherein, in terms of a showerhead,

a plurality of source gas ejection ports are arranged in a crossing direction crossing the two directions of the four directions along the film formation surface to constitute a source gas ejection port group,

In the intersecting direction, a plurality of ozone gas ejection ports are arranged to constitute an ozone gas ejection port group.

12. The atomic layer deposition method according to any one of claims 6 to 11, wherein the dimension in the two directions of each ejection port of the showerhead is in a range of 1mm to 50mm, and the distance between the two ejection ports and the film formation surface of the object to be film-formed is in a range of 1mm to 20 mm.

13. The atomic layer deposition method according to any one of claims 6 to 12, wherein at least any one of the ejection orifices of the showerhead is long in a slit shape in a crossing direction crossing the two directions of four directions along the film formation surface.

14. The atomic layer deposition method according to any one of claims 6 to 13, wherein a gas supply amount of the source gas is set to 0.0001 to 1sccm per unit length of the source gas ejection port in a direction perpendicular to the two directions,

the amount of ozone gas supplied is set to be 0.1sccm to 10sccm per unit length in the direction perpendicular to the two directions of the ozone gas discharge port.

15. The atomic layer deposition method according to any one of claims 2 to 4, wherein the chamber has:

A raw material gas treatment furnace provided with a raw material gas outlet,

Ozone gas treatment furnace provided with ozone gas discharge port, and ozone gas treatment method

An inert gas treatment furnace provided with an inert gas outlet between the raw material gas treatment furnace and the ozone gas treatment furnace,

the support part has:

one end side roller for winding and supporting one end side of a film forming object,

A second end roller for winding and supporting the second end of the object to be formed,

1 st turn-back roller arranged in raw material gas treatment furnace, and

the 2 nd turn-back roller arranged in the ozone gas treatment furnace is a roller-to-roller type structure which can support the object to be formed in a movable manner in two opposite directions of four directions along the surface to be formed,

the object to be film-formed between one end side roller and the other end side roller is folded back by the 1 st and the 2 nd folding rollers and extended in a zigzag manner to and fro and overlapped at two positions in the raw material gas treatment furnace and the ozone gas treatment furnace,

each time the gas is moved between the raw material gas treatment furnace and the ozone gas treatment furnace, the gas is passed through the inactive gas treatment furnace,

the furnace walls of the respective processing furnaces are provided with processing furnace openings through which the film formation target is passed at positions intersecting the meandering film formation target.

16. The atomic layer deposition method according to claim 15, wherein, in the curved path of movement of the object to be film-formed,

a position between the 1 st turn-back roller and the processing furnace opening in the raw material gas processing furnace and opposite to the processing furnace opening, and

at least one position of the 2 nd turning roll and the position opposite to the opening of the treatment furnace between the two rolls is provided with a position adjusting roll.

17. The atomic layer deposition method according to any one of claims 1 to 16, wherein the cycle of each step of the raw material gas supply step, the raw material gas purge step, the oxidizing agent supply step, and the oxidizing agent purge step is performed a plurality of times, and different types of raw material gases are supplied to the object to be deposited in at least 1 step and the remaining steps of each raw material gas supply step.

18. The atomic layer deposition method according to any one of claims 1 to 17, wherein the oxide film contains Al ₂ O ₃ 、HfO ₂ 、TiO ₂ 、ZnO、Ta ₂ O ₃ 、Ga ₂ O ₃ 、MoO ₃ 、RuO ₂ 、SiO ₂ 、ZrO ₂ 、Y ₂ O ₃ An adsorption layer of any one of the above.

19. The atomic layer deposition method according to any one of claims 1 to 18, wherein the object to be film-formed is heated or not heated in a range of 100 ℃ or less.

20. The atomic layer deposition method according to any one of claims 1 to 19, wherein an exposure amount of the source gas in the source gas supply step to the film formation surface is set to 1 x 10 ⁴ Langmuir above.

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