JPH04145621A - Semiconductor thin film vapor growth device - Google Patents

Abstract

PURPOSE:To improve corrosion resistance and safety and to assure crystal quality by coating inside of a raw material container and a piping for raw gas with a specified metallic film. CONSTITUTION:Inside of a raw gas container of a metallic material and a piping which raw gas passes through is coated with a metallic film tantalum- base tantalum alloy containing 50% or less tungsten; thereby, corrosion resistance and safety are improved and thin film vapor growth whose crystal quality is assured can be carried out using oxidizing or reducing raw gas.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a semiconductor 1m vapor phase growth apparatus that improves the corrosion resistance of raw material containers and piping parts.

(Prior art and its problems) As a vapor phase growth apparatus for growing semiconductor thin films, metal organic vapor phase growth apparatus, chloride V, P, E apparatus, halide V,
There are P and E devices.

Among these devices, for example, there is an organometallic vapor phase growth device as shown in FIG. 1. In FIG. 1, (1) is a reaction vessel made of quartz or stainless steel, (2) is a susceptor made of carbon, (3) is a semiconductor substrate, and (4) is an induction coil for heating the substrate. To grow an InP/IrGaAsP-based crystal thin film using this device, for example, the susceptor (2) and semiconductor substrate (3) are heated to 500 to 800°C by the induction coil (4) in the reaction vessel (1). Trimethylgallium (TMG) is diluted with H2 gas through a stainless steel raw material supply pipe (8).
a), organometallic gases such as trimethylindium (TMIn) and arsine (AsHs) phosphine (PH3
), etc., and by utilizing the thermal decomposition reaction of these raw material gases, InP/InCaA is formed on the semiconductor substrate.
An sP-based crystal thin film is formed. Of the raw material gas,
Hl is flammable, and organometallic gases such as TMGa STMIn spontaneously ignite when exposed to air.

Furthermore, ASHs, PHx, etc. are extremely harmful to the human body. Therefore, in the structure of an organometallic growth apparatus that uses these raw material gases, the strength of reaction vessels, piping, connections, etc. must be ensured to ensure that these raw material gases do not leak.
It is necessary to design with corrosion resistance in mind.

In addition, in the above-mentioned apparatus, Ga, In, As, P, etc. generated by thermal decomposition of the raw material gas during crystal thin film growth adhere to and accumulate on the inner wall of the reaction vessel and the surface of the susceptor, which adversely affects the composition and surface condition of the crystal thin film. To prevent this, a corrosive gas raw material container (5) such as HCl or P (1) is used to periodically remove deposits on the surface of the reaction vessel and susceptor.
is installed in the piping line.

Various problems remain when using the above corrosive raw material gas. For example, the PCffi3 mentioned above corrodes metal materials such as stainless steel even at room temperature, so glass is used for this raw material gas container, and the PCffi3
Resin materials such as glass and Teflon are also used for the corrosive gas pipe (6) and the corrosive gas pulp (7) that supply x to the reaction vessel. However, glass is highly susceptible to breakage due to mechanical impact, and if Teflon is used, there is a risk of leakage at connections.

In addition, since the H(l raw material PCj!3 is not highly corrosive, it is sealed in a raw material container (22) made of stainless steel, etc., and is installed in stainless steel piping (9) and a stainless steel pressure reducing valve (1).
0), pulp (11), flow rate regulator (12), and other piping parts are used, and the raw material is supplied into the reaction vessel through a raw material supply pipe (8) also made of stainless steel.

However, the HC1 raw material becomes corrosive to the above-mentioned stainless steel raw material containers and piping parts, especially when a small amount of moisture is present, causing holes in the piping parts, or stainless steel being incorporated into the gas due to corrosion. constituent elements may be carried into the reaction vessel and adversely affect the quality of crystalline Ti1H.

On the other hand, the exhaust pipe (13) and valve (14) downstream of the reaction vessel
are also made of stainless steel and have the same problem with the corrosive gases mentioned above. Furthermore, since the exhaust pipe comes into contact with H2 gas heated by the susceptor, there is a problem that hydrogen embrittlement of the stainless steel material may occur in the long term.

As described above, many raw material containers and piping parts made of stainless steel are used in organometallic vapor phase growth apparatuses, but they have a problem in corrosion resistance against corrosive gases.

Further, in a similar semiconductor 'ril film vapor phase growth apparatus, for example, A s CIls, P Cj! Chloride V, P, E equipment that uses s gas etc. uses corrosive gas even during the production of crystal thin films, so the problem is the same as above, or
It's more serious than that.

[Problems to be Solved by the Invention] The present invention has been made as a result of studies on the above problems, and has excellent corrosion resistance against oxidizing or reducing raw material gases, improves safety, and We have developed a semiconductor thin film vapor phase growth system that can guarantee the quality of crystals.

[Means and effects for solving the problems] The present invention uses a raw material gas having an oxidizing or reducing property, and provides a semiconductor thin film vaporizer in which at least the raw material container for the raw material gas or the piping parts through which the raw material gas passes are made of metal. The present invention is a semiconductor thin film vapor phase growth apparatus characterized in that the inner surface of the raw material container or the piping component through which the raw material gas passes is coated with a metal film containing tantalum as a main component.

That is, the present invention provides tantalum in all or part of the raw material container, piping, flow rate regulator, pressure reducing valve, valves, etc. that come into contact with the corrosive gas of a semiconductor vapor phase growth apparatus. Corrosion resistance and safety are improved by coating with a tantalum alloy metal film containing tantalum.

〔Example〕

Examples of the present invention will be described below.

For example, in the organometallic vapor phase growth apparatus shown in FIG. 1, at least the corrosive gas raw material container (5) and the raw material container (22), the corrosive gas pipe (6) through which the raw material gas passes, the corrosive gas valve (7), and the raw material Stainless steel pipes and pipes such as supply pipes (8), stainless steel pipes (9), pressure reducing valves (10), valves (11), flow regulators (12), exhaust pipes (13), valves (14), etc. All or part of the parts are coated with a metal film containing tantalum as the main component on the inner surface that comes into contact with corrosive gas.

For example, regarding the corrosive gas raw material container (5), as shown in FIG. 2, the inner surface of the container base (15) made of stainless steel, which is in contact with the corrosive gas, contains a metal whose main component is tantalum! I
(16) Cover. Also, corrosive gas piping (6), raw material supply pipe (8), stainless steel piping (9), exhaust pipe (13)
), the inner surface of a stainless steel pipe base (18) is coated with a metal film (16) containing tantalum as a main component, as shown in FIG.

Furthermore, the pressure reducing valve (10), valves (11), (14), flow rate regulator (12), etc. are also coated with a metal film containing tantalum as a main component on the inner surface that comes into contact with the corrosive gas, as in the case of the raw material container described above. There are 2 types of coatings.

The metal film containing tantalum as a main component may be tantalum or a tantalum alloy containing tantalum and 50% or less of tungsten.

The metal films of tantalum and tantalum alloys mentioned above are corrosion resistant to almost all acids except hydrofluoric acid (HCl).
, PCI'+, AsCj! It is not corroded by oxidizing and corrosive gases such as .

This is a Ta oxide film (Ta*
This is because O1 has excellent corrosion resistance. Therefore, the safety problems caused by the corrosion of the raw material containers and piping described above are resolved.

In addition, it has excellent corrosion resistance against highly corrosive raw materials such as PCN, so there is no need to use conventional glass or resin raw material containers and piping parts, and this reduces mechanical strength and leakage. Problems are also reduced.

Furthermore, when used in the above-mentioned exhaust pipe, since tantalum is difficult to cause hydrogen embrittlement, the service life will be significantly longer than that of conventional stainless steel.

Tantalum has poor corrosion resistance to hydrofluoric acid, but a Ta-W alloy containing tantalum and tungsten has improved corrosion resistance to hydrofluoric acid, so when using a corrosive gas such as ClF5, it is recommended to coat this alloy. Effective.

Therefore, it is preferable that the thickness of the metal film is approximately 0.05 to 1.0 mm.If the thickness is less than this, problems such as uniformity of the coating layer and pinholes will occur, and sufficient corrosion resistance will not be obtained. If it exceeds (2), economic problems may arise depending on the size of the raw material container and the length of the piping. Therefore, the thickness of the metal film can be appropriately set depending on the shape and dimensions of the raw material container, piping, etc. without being limited to the piping described above.

Furthermore, as shown in FIG. 4(a), the above-mentioned method of coating a metal film can be applied directly to the surface of a substrate (19) such as stainless steel.
The tantalum film (20) can be formed using the thermal spraying method or the explosion bonding method, but if the adhesion between the substrate and the coating metal is a problem, (as shown in Figure b1) Adhesion can be improved by interposing an intermediate layer (21) of a copper alloy such as copper-Ninokel.

In the above example, the base materials such as the raw material container, corrosive gas piping, and flow rate regulator are made of stainless steel, but the same effect can be obtained even if these materials are coated with aluminum or other metals.

In addition, the present invention can coat all or some parts of a vapor phase growth apparatus that come into contact with corrosive gas, making it difficult to install.
It is selected and applied taking economic considerations into account.

Furthermore, the semiconductor thin film vapor phase growth apparatus targeted by the present invention includes:
The above-mentioned organometallic vapor phase epitaxy apparatus and chloride V, P,
It can be applied to vapor phase growth apparatuses that use source gases having oxidizing or reducing properties, as well as E apparatuses, halide V, P, and E apparatuses.

In addition, semiconductor materials include rnP/InGaAsP, GaAs/
The present invention can also be applied to growth apparatuses for ordinary semiconductor materials such as AllGaAs and St.

〔effect〕

As explained above, according to the present invention, the corrosion resistance and safety of a semiconductor thin film vapor phase growth apparatus are improved, and it also contributes to improving the quality of crystals, which is an industrially significant effect.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a semiconductor thin film vapor phase growth apparatus according to an embodiment of the present invention, FIG. 2 is a sectional view of a corrosive gas raw material container according to an embodiment of the present invention, and FIG. 3 is a schematic diagram of a semiconductor thin film vapor phase growth apparatus according to an embodiment of the present invention. FIG. 4 is a sectional view of a pipe according to an embodiment of the present invention, and is a sectional view illustrating a method of coating with a metal film according to an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Reaction container, 2... Susceptor, 3... Semiconductor substrate, 4... Induction coil, 5... Corrosive gas raw material container, 6... Corrosive gas piping.

Claims (4)

[Claims] (1) In a semiconductor thin film vapor phase growth apparatus that uses a raw material gas having oxidizing or reducing properties and in which at least the raw material container for the raw material gas or the piping parts through which the raw material gas passes are made of metal, A semiconductor thin film vapor phase growth apparatus characterized in that the inner surface of the piping parts that it passes through is coated with a metal film containing tantalum as a main component. (2) The semiconductor thin film vapor phase growth apparatus according to claim 1, wherein the metal film containing tantalum as a main component is tantalum and a tantalum alloy containing 50% or less of tungsten in tantalum. (3) The thickness of the metal film whose main component is tantalum is 0.05
Claim 1 or 2 characterized in that the diameter is 1.0 mm.
The semiconductor thin film vapor phase growth apparatus described above. (4) Claim 1 characterized in that an intermediate layer of copper or a copper alloy containing copper as a main component is interposed between the metal film containing tantalum as the main component and the base of the raw material container or piping component.
or 2. The semiconductor thin film vapor phase growth apparatus according to 2.