JP2002097092A - Glassy carbon material coated with silicon carbide film and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a glassy carbon material coated with SiC film, which is suitably employed as a heat treatment member for a semiconductor producing apparatus and also as a heat resistant member used in the atmosphere of high temperature and of high purity, and provide a method for producing the same. SOLUTION: The SiC film is coated on the glassy carbon material by a chemical vapor deposition(CVD) method, the X-ray diffraction peak strength of the SiC crystal face (111) of the film is <=10 kc.p.s, and the diffraction peak strength of the SiC crystal face (111) is >=80% of the diffraction peak strength of the whole crystal faces (hkl). The above diffraction peak strength is determined under the following conditions: X-ray source is Cuk α; tube bulb voltage is 40 kV; tube bulb current is 20 mA; filter is Ni-filter; divergent slit is 1 deg., scattering slit is 1 deg.; and light receiving slit is 0.3 mm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a glass coated with a SiC film which is suitably used as a member for semiconductor manufacturing equipment such as a susceptor, a process tube, a wafer boat or the like, and an oxidation-resistant and heat-resistant member used in a high-temperature, high-purity atmosphere. Carbonaceous material.

[0002]

2. Description of the Related Art A glassy carbon material having excellent properties such as gas impermeability, abrasion resistance, corrosion resistance, surface smoothness, etc.
A glass-like carbon material coated with a high-purity, dense SiC film by CVD and further improved in properties such as high-temperature oxidation resistance is used as a member for semiconductor manufacturing equipment such as process tubes and wafer boats. (JP-A-3-217016, etc.).

A glassy carbon material coated with a SiC film has excellent characteristics as compared with quartz or the like which has been conventionally used as a member for semiconductor manufacturing equipment. Due to the difference in the coefficients, cracks occur in the cooling process after film formation, and the SiC film peels off, and there is a demand for improvement.

[0004] In order to solve the above-mentioned problems, the present inventors have previously set the gas phase pyrolysis temperature at the time of coating the glassy carbon material with the SiC film by performing the gas phase pyrolysis of the raw material gas by the CVD method. By gradually increasing the temperature from the initial film forming process to the final film forming process and maintaining the gas phase temperature in the final film forming process for a predetermined time, the heat shock resistance is high, and the glassy carbon material and SiC
A method for producing a glassy carbon material coated with a SiC film having excellent adhesion to the film was proposed (Japanese Patent Application No. 11-225901).

According to this method, the occurrence of cracks due to thermal cycling is reduced, and a glassy carbon material coated with a SiC film having improved adhesion can be obtained. However, in recent years, due to a demand for a large-sized member for a semiconductor manufacturing apparatus in accordance with an increase in the diameter of a silicon wafer, an increase in the size of a glassy carbon material coated with a SiC film as a member has been studied.
If the film-coated glassy carbon material is enlarged, cracks are more likely to occur due to the difference in thermal expansion coefficient between the SiC film and the glassy carbon material. It has been clarified that the above-described problems in the case of a large-sized carbon material cannot be solved even when the size is increased.

[0006]

SUMMARY OF THE INVENTION The present invention relates to a process for studying the crystal structure of SiC in a SiC film.
This is based on the finding of the relationship between the properties of the SiC crystal plane and the thermal shock resistance.
The SiC film-coated glassy carbon material coated with the SiC film by the method has excellent thermal shock resistance and oxidation resistance that can withstand thermal shock due to rapid heating and rapid cooling even when the size is increased. An object of the present invention is to provide a SiC film-coated glassy carbon material having good adhesion and a SiC film firmly adhered thereto, and a method for producing the same.

[0007]

According to a first aspect of the present invention, there is provided a glass-like carbon material coated with a SiC film by a CVD method. Of SiC film by X-ray diffraction
The diffraction peak intensity of the iC (111) crystal plane is 10 kc.
p. s or less, and the diffraction peak intensity of the SiC (111) crystal plane is 80% of the diffraction peak intensity of the entire crystal plane (hkl).
% Or more. However, the above-mentioned diffraction peak intensity means that CuKα is an X-ray source, a tube voltage is 40 kV,
This refers to the peak intensity when the tube current is 20 mA, the Ni filter is used, the divergence slit is 1 °, the scattering slit is 1 °, and the light receiving slit is 0.3 mm.

[0010] In the glass-like carbon material coated with the SiC film according to claim 2, the thickness of the SiC film is 5 to 3 in claim 1.
It is characterized by being 0 μm.

Further, the method for producing a glassy carbon material coated with a SiC film according to claim 3 is characterized in that the method comprises the steps of:
A method for producing a film-coated glassy carbon material, comprising:
Gas into the glassy carbon material by pyrolysis
In coating the iC film, the gas phase pyrolysis temperature was set at 1050 to 1050.
The temperature is 1150 ° C.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The glassy carbon material applied in the present invention is not particularly limited, and a phenol-based, furan-based, polyimide-based, etc. thermosetting resin is molded and cured as a raw material as in the prior art. It is obtained by heating to a temperature of, for example, 800 ° C. or more in a non-oxidizing atmosphere, followed by calcining and carbonizing. Materials used as heat treatment members for semiconductor manufacturing are heated to about 2000 ° C. in a halogen gas atmosphere to be highly purified, and are further provided with a surface roughness Ra: 0.4 to
It is preferable to have a surface texture of 15 μm. Ra: 0.4
If it is less than μm, it will be easy to peel off, and if it exceeds Ra: 15 μm, the strength of the substrate will decrease.

S by CVD for glassy carbon material
The deposition of the iC film is performed by setting a glassy carbon substrate as a substrate in a CVD reactor, exhausting air in the reaction system, heating the gas to a predetermined temperature, and thermally decomposing a raw material gas in a gas phase. S on the surface
This is performed by depositing iC and depositing a SiC film. The source gas contains Si and C atoms in one molecule, such as trichloromethylsilane (CH ₃ SiCl ₃ ), dichloromethylsilane (CH ₃ SiHCl ₂ ), and trichlorophenylsilane (C ₆ H ₅ SiCl ₃ ). Halogenated organosilicon compounds are used, and these raw material gases are fed into a reaction chamber together with a carrier gas, hydrogen gas, to be reduced in the gas phase and thermally decomposed, or silicon compounds such as carbon tetrachloride (SiCl ₄ ). And a carbon compound such as methane (CH ₄ ) are fed into the reaction chamber together with the carrier gas hydrogen or argon gas to cause a gas phase reaction to precipitate SiC, which is deposited on the base surface of the glassy carbon material. Let it.

In the present invention, in a SiC film coated on a glassy carbon material by a CVD method, the diffraction peak intensity of the SiC (111) crystal plane of the SiC film measured by X-ray diffraction is 10 kc. p. s or less, and the SiC
The diffraction peak intensity of the (111) crystal plane is
1) It is characterized by being 80% or more of the diffraction peak intensity. However, the diffraction peak intensity means that CuKα is an X-ray source,
The peak intensity when the tube voltage is 40 kV, the tube current is 20 mA, and a Ni filter is used, and the divergence slit is 1 °, the scattering slit is 1 °, and the light receiving slit is 0.3 mm.

The diffraction peak intensity of the SiC (111) crystal plane of the SiC film is 10 kc. p. s is exceeded, or
When the diffraction peak intensity of the SiC (111) crystal plane is less than 80% of the diffraction peak intensity of the entire crystal plane (hkl),
The thermal shock resistance of the glass-like carbon material coated with the SiC film becomes insufficient, cracks are likely to occur in a thermal cycle, and the adhesion of the SiC film also decreases.

The thickness of the SiC film formed on the glassy carbon material is preferably 5 to 30 μm, and if it is less than 5 μm, the SiC film
There is a high possibility that there is a portion not covered with the film or a portion with a very thin film thickness, and sufficient oxidation resistance may not be obtained. If the thickness exceeds 30 μm, cracks and peeling are likely to occur after film formation. .

In the production of the SiC film-coated glassy carbon material according to the present invention, in the step of forming the SiC film on the glassy carbon material, ie, in the step of feeding the raw material gas to cause the gas phase pyrolysis reaction, The reaction is preferably performed by adjusting the gas flow rate, the carrier gas flow rate, or the ratio of these gas flow rates, and setting the reaction temperature to 1050 to 1150 ° C. Of these, the reaction temperature is a very important requirement in the production of the glassy carbonaceous material coated with the SiC film of the present invention. Even when a normal gas flow rate is applied, the reaction in the above temperature range causes the reaction of the SiC film coated with the present invention. In many cases, production of glassy carbon materials is possible.

When the reaction temperature is lower than 1050 ° C., free Si is easily generated in the SiC film, and the chemical resistance and oxidation resistance are lowered. When the reaction temperature exceeds 1150 ° C., the formed Si
The diffraction peak intensity of the SiC (111) crystal plane of the C film is 10
kc. p. When the reaction temperature is further increased, the diffraction peak intensity of the SiC (111) crystal plane is apt to be less than 80% of the diffraction peak intensity of the entire crystal plane (hkl), and cracks and peeling occur in the SiC film in any case. There is a risk.

The raw material gas flow rate, the carrier gas flow rate,
Or just adjusting the ratio of these gas flow rates,
Although there are problems such as a decrease in the film formation rate and a decrease in the uniformity of the film thickness,
The production of a glassy carbon material coated with a SiC film according to the present invention is possible.

[0018]

Hereinafter, examples of the present invention will be described in comparison with comparative examples. These examples show one embodiment of the present invention, and the present invention is not limited to these.

Example 1 A phenolic resin precondensate prepared from phenol and formalin produced by distillation under reduced pressure was poured into a polypropylene vat (mold), degassed under a reduced pressure of 10 Torr for 3 hours, and then heated at 80 ° C. It was placed in an electric oven and molded.

Then, the mold was taken out of the mold, heated to 180 ° C. at a rate of 10 ° C./hour, and held for 24 hours to cure. The cured resin molded body is placed in an electric furnace while being sandwiched between high-purity graphite plates, and its surroundings are covered with graphite powder having a total ash content of less than 100 ppm, and heated to 1000 ° C. at a rate of 2 ° C./hour. And then transferred to a vacuum furnace in which the atmosphere can be replaced, and supplied with a purified gas of chlorine / helium (molar ratio: 5/95) into the furnace at a rate of 5 L / min.
The temperature was raised to ° C. to perform a high-purity treatment, and a surface treatment for obtaining a more preferable surface roughness (Ra) was performed.

The high-purity glassy carbon material obtained in the above process was processed to a length of 300 mm, a width of 300 mm, and a thickness of 4 mm, set in a reaction tube of a CVD reactor, and exhausted air from the system. Then, it is heated to a predetermined temperature,
Under Pa), a hydrogen gas was fed to replace the atmosphere with a hydrogen gas atmosphere. Next, using trichloromethylsilane (CH ₃ SiCl ₃ ) as a raw material gas and hydrogen as a carrier gas, a flow rate ratio of trichloromethylsilane (CH ₃ SiCl ₃ / H ₂ vol
%) And the reaction temperature to change the glassy carbon material to SiC.
The membrane was coated. Trichloromethylsilane flow rate ratio,
Table 1 shows the reaction temperature (film formation temperature) and the surface roughness of the glassy carbon material.

The produced SiC film-coated glassy carbon material (test materials Nos. 1 to 3) was obtained by the following method.
Measurement of the thickness of the SiC film, X-ray diffraction of the surface of the SiC film, observation of the appearance (presence or absence of color spots, cracks, and peeling), a thermal shock test, and an oxidation resistance test were performed. The results are shown in Tables 1 and 2. Measurement of the thickness of the SiC film: By cutting the glassy carbon material coated with the SiC film and observing the cross section by SEM,
The thickness of the iC film is measured.

X-ray diffraction of the surface of the SiC film: X-ray diffraction of the surface of the SiC film determines the diffraction peak intensities of the SiC (111) crystal plane and the entire crystal plane (hkl).
The diffraction peak intensity ratio of the SiC (111) crystal plane to the diffraction peak intensity of 1), (111) / Σ (hkl), was calculated. As described above, the X-ray diffraction was performed using CuKα as an X-ray source, a tube voltage of 40 kV, a tube current of 20 mA, and a Ni filter using a Ni filter at 1 ° for a divergence slit, 1 ° for a scattering slit, and a light receiving slit. Performed using 0.3 mm.

Thermal shock test: A glassy carbon material coated with a SiC film was put into an electric furnace heated to 1200 ° C. at a stretch,
After holding at 1200 ° C. for 10 minutes, a thermal cycle test in which the sample was taken out of the furnace at a stretch and cooled to 200 ° C. was repeated, and the number of tests when cracks and peeling occurred in the SiC film was obtained. However, in this example, the situation after performing the heat cycle test 50 times is shown.

Oxidation resistance test: 100 in air atmosphere
The weight after holding at a temperature of 0 ° C. for 24 hours was measured to calculate a weight loss rate.

[0026]

[Table 1]

[0027]

[Table 2]

As shown in Tables 1 and 2, the test material No. Each of Nos. 1 to 5 has no cracks even after repetition of 50 heat cycles, has less than 0.1% in weight loss by oxidation, and has excellent thermal shock resistance and oxidation resistance. I have.

Comparative Example 1 A high-purity glassy carbon material was prepared in the same manner as in Example 1, and the obtained high-purity glassy carbon material was prepared by the same method as in Example 1 (trichloromethylsilane / hydrogen). The concentration of trichloromethylsilane (vol.% Of CH ₃ SiCl ₃ / H ₂ ) and the reaction temperature in the mixed gas of (Gas) were changed to cover the SiC film of the glassy carbon material. Table 1 shows the ratio of the flow rate of trichloromethylsilane, the reaction temperature (film formation temperature), and the surface roughness of the glassy carbon material.

For the manufactured SiC film-coated glassy carbon material (test materials Nos. 6 to 12), the thickness of the SiC film was measured by the same method as in Example 1, and the X on the surface of the SiC film was measured.
Line diffraction, appearance observation (color spots, cracks, presence or absence of peeling), thermal shock resistance test, and oxidation resistance test were performed. Table 3 shows the results
Are shown in FIGS.

[0031]

[Table 3] << Table note >> SiC (111) plane diffraction peak intensity *: Si peak

[0032]

[Table 4]

As shown in Tables 3 and 4, the test material No. Sample No. 6 has a thin SiC film, causing color spots, and has poor oxidation resistance. Test material No. 7 has a thick SiC film, so cracks are observed after the formation of the SiC film, cracks are generated in a thermal shock test, and the oxidation resistance is poor. Test material No. 8
Since the film formation temperature is low, a peak of Si is required by X-ray diffraction, and the oxidation resistance is poor. Test material No. 9, No. Since No. 10 has a high film forming temperature, cracks and film peeling are observed after film formation, and the film has poor oxidation resistance. In addition, as a result of performing an oxidation resistance test on a glassy carbon material on which no SiC film was formed, the weight loss rate due to oxidation consumption was extremely large at 6.15%. Test material No. No. 11 has a small surface roughness of the glassy carbon material as the base material, so cracks are observed after the formation of the SiC film, and film peeling is observed in the thermal shock test, resulting in poor thermal shock resistance and oxidation resistance. Was. Test material No. In No. 12, since the surface roughness of the glassy carbon material as the base material is large, cracks occur in the thermal shock test, and the thermal shock resistance and the oxidation resistance are poor.

[0034]

As described above, according to the present invention, a glassy carbon material coated with a SiC film having excellent thermal shock resistance and oxidation resistance and a method for producing the same are provided. The SiC film-coated glassy carbon material has various heat treatment members used in semiconductor manufacturing, such as a guide ring, a susceptor, a liner tube, a process tube, a wafer boat, a device for pulling a single crystal, and a thermal shock resistance and an oxidation resistance. It can be suitably used as required various heat resistant members.

Continued on front page (72) Inventor Kenzo Okamoto 1-3-2 Kitaaoyama, Minato-ku, Tokyo Tokai Carbon Co., Ltd. F-term (reference) 4G032 AA07 AA33 BA00 BA01 GA19 4K030 AA03 AA06 AA09 AA17 BA37 CA01 DA03 FA10 JA01 JA10 JA20 LA11 5F004 BB29 5F045 AB06 EB03 EC05 EM09

Claims (3)

[Claims] 1. Si coated with a SiC film by a CVD method
In a C-film-coated glassy carbon material, X-ray diffraction
The diffraction peak intensity of the SiC (111) crystal plane of the C film is 10
kc. p. s or less, and the diffraction peak intensity of the SiC (111) crystal plane is 80% or more of the diffraction peak intensity of the entire crystal plane (hkl). However, the diffraction peak intensity means that CuKα is X
The source, the tube voltage is 40 kV, the tube current is 20 mA,
This refers to the peak intensity when using a Ni filter, 1 ° for the divergence slit, 1 ° for the scattering slit, and 0.3 mm for the light receiving slit. 2. The glassy carbon material coated with a SiC film according to claim 1, wherein the thickness of the SiC film is 5 to 30 μm. 3. A method of coating a glassy carbon material with a SiC film by vapor-phase pyrolysis of a raw material gas by a CVD method,
The method for producing a glassy carbon material coated with a SiC film according to claim 1 or 2, wherein the gas phase pyrolysis temperature is set to be from 1050 to 1150 ° C.