JPH05330955A - Silicon carbide-metallic silicon composite material and its production - Google Patents

Abstract

PURPOSE:To form a silicon carbide film by heating a silicon carbide-metallic silicon composite material in a neutral or inert atmosphere having a carbon monoxide concentration higher than a specific level at a temperature within a specific range, thereby converting the metallic silicon on the surface layer into silicon carbide. CONSTITUTION:A silicon carbide-metallic silicon composite material is heated at 1100-1420 deg.C in a neutral or inert gas atmosphere having a carbon monoxide concentration of >=2% to uniformly convert the metallic silicon on the surface layer into silicon carbide. The thickness of the formed silicon carbide layer is preferably >=150mum from the viewpoints of economy and the prevention of the layer from peeling.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a silicon carbide-metal silicon composite material used as a wafer boat, a heat equalizing tube, etc. of a semiconductor manufacturing member, and a method for manufacturing the same. Silicon carbide characterized in that a silicon carbide film formed by converting silicon into silicon carbide is formed.
TECHNICAL FIELD The present invention relates to a metal-silicon composite material and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, a quartz glass member has been widely used as a semiconductor manufacturing member because gas impermeability is required. However, since the quartz glass member has a problem of devitrification and sag due to impurity contamination, a silicon carbide-metal silicon composite material in which metallic silicon is impregnated into open pores of porous silicon carbide is widely used. Used.
However, when a wafer boat is formed from the composite,
During cleaning with an HF-HNO ₃ mixed acid, the metal silicon portion is eluted, the porous silicon carbide portion is exposed on the surface, and particles may be generated during loading and unloading into the diffusion furnace. On the other hand, in order to improve such a defect, silicon carbide is vapor-deposited on the surface of a silicon carbide-metal silicon composite to produce a member for semiconductor production having a dense silicon carbide film. A method has been proposed. However, in the silicon carbide film obtained by this method, for example, when pinholes are generated, the mixed acid enters into the pinholes during the washing with the above-mentioned HF-HNO ₃ mixed acid, and the film peeling occurs during the temperature rising process. It may occur. Also, the gas used is very expensive, and the resulting product is also very expensive.

[0003]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention The present invention has been made in order to solve the above-mentioned problems. In the silicon carbide-metal silicon composite material, the silicon carbide portion exposed on the surface is silicon carbide. It is to produce the composite material in which the entire surface is made of silicon carbide by converting it to a raw material. The present invention has found that since the silicon metal portion is converted into silicon carbide, there is no peeling of the film that occurs when a pinhole occurs, and the film can be manufactured at low cost.

[0004]

[Means for Solving the Problems] That is, according to the present invention, the obtained silicon carbide-metal silicon composite is treated in an atmosphere in which the carbon monoxide gas concentration in the neutral or inert gas is 2% or more. It is characterized by heating in a temperature range of 1100 ° C to 1420 ° C.

[0005]

The present invention will be described in detail below. Silicon Carbide-
When the metal-silicon composite material is placed in a neutral or inert gas atmosphere in which a certain amount or more of carbon monoxide gas is present in the furnace, the surface silicon metal becomes 2Si + CO → SiC + S.
The reaction of iO (formula) proceeds, and as a result, the silicon metal in the surface portion is converted into silicon carbide, and silicon monoxide gas is released. As a result of repeating various experiments, 1100 ° C to 1
It was found that when the carbon monoxide gas concentration in the furnace atmosphere gas was 2% or more in the temperature range of 420 ° C., the reaction of the equation proceeded and the silicon metal on the surface was uniformly converted to silicon carbide. It was The reason why the treatment temperature is set to 1100 ° C or higher is 1
When the temperature was 100 ° C. or lower, the silicon carbide was partially converted, but the metal silicon on the entire surface was not converted. Again 1
The reason why the temperature is 420 ° C. or lower is that the melting point of metallic silicon is 1420.
This is because the melting point of the metal silicon causes the film thickness to become non-uniform due to the behavior of the metal silicon. Also, the reason for setting the carbon monoxide concentration to 2% or more is that it is 2% or less,
Although it was partially converted to silicon carbide, the silicon metal on the entire surface was not converted. By the way, regarding the film thickness, it was found that the metal silicon on the surface portion was converted into silicon carbide in a certain time up to 150 μm, but thereafter the film thickness gradually became gradual. It was found that the thickness of 150 μm or less is sufficient for the economical reason and the purpose of peeling the film, which is the purpose of the present invention. Regarding the carbon monoxide gas, a method of introducing the carbon monoxide gas into the furnace, or reacting a small amount of oxygen gas existing in the furnace with the carbon that has been put in advance, the carbon monoxide concentration is changed. It may be formed by 2% or more.

[0006]

EXAMPLE A silicon carbide-metal silicon composite material was exposed to 1050 in an Ar atmosphere with a carbon monoxide concentration of 2%.
C., 1100.degree. C., 1200.degree. C., and 1450.degree. C. were heat-treated. For comparison, the same composite material as above was used for Ar.
12 in an atmosphere with a carbon monoxide concentration of 1%
Heat treatment was performed at 00 ° C. Each of the obtained silicon carbide-
After immersing the metal-silicon composite material in HF-HNO ₃ mixed acid, the elution amount of metal silicon was measured by weight change. Also, the film thickness of the converted silicon carbide was measured. The results are shown in Table 1. 120% of carbon monoxide concentration of 2% at 1050 ° C
A carbon monoxide concentration of 1% at 0 ° C showed a weight reduction before and after washing with HF-HNO ₃ , and since it was not entirely converted to silicon carbide, metal silicon was eluted and the weight was reduced. .. If the carbon monoxide concentration is 2% at 1450 ° C,
It can be seen that there is a large variation in the film thickness of the converted silicon carbide. As described above, the product of the present invention has no weight change before and after washing with HF-HNO ₃ and the film thickness of the converted silicon carbide is uniform.

[0007]

As described above, according to the present invention, the surface portion of the silicon carbide-metal silicon composite has been converted into silicon carbide having a uniform film thickness, and vapor phase vapor deposition was carried out. Since it is obtained at low cost for a silicon carbide film and there is no concern that the film will be peeled off, it is optimal as a silicon carbide material for semiconductor production and is extremely useful industrially.

[Table 1] In the above, No. Case 3 and general silicon carbide −
Vapor deposition of silicon carbide on metal-silicon composites 100 μm
The coated cases were compared. In terms of manufacturing cost, the embodiment of the present invention is significantly cheaper, which is 1/3 that of vapor deposition of silicon carbide. In addition, No. Using the vapor deposition products of 3 and silicon carbide, rapid heating and cooling tests were conducted. The test conditions are
Place in a muffle furnace maintained at 200 ° C for 10 minutes,
After heating, it was immediately taken out of the muffle furnace, immersed in water at about 20 ° C. and rapidly cooled, and this was repeated until cracks were generated. The vapor-deposited product of silicon carbide generated cracks at the 20th time. However, no. In the case of 3, no crack was generated.

Claims (3)

[Claims] 1. A silicon carbide-metal silicon composite material, wherein a silicon carbide film is formed by converting the metal silicon of the surface portion into silicon carbide-a silicon carbide-
Metal-silicon composite material. 2. The silicon carbide-metal silicon composite material according to claim 1, wherein the silicon carbide film has a thickness of 150 μm or less. 3. A silicon carbide-metal silicon composite material is heated in a temperature range of 1100 ° C. to 1420 ° C. in an atmosphere having a carbon monoxide concentration of 2% or more in a neutral or inert gas atmosphere, The silicon carbide-metal silicon composite material according to claim 1, wherein the silicon metal on the surface portion is converted into silicon carbide.