JP2003268548A - SiC FILM-FORMED GLASSY CARBON STOCK - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an SiC film-formed glassy carbon material which is suitably as a heat resistant member used in a high temperature, high purity atmosphere including members of a semiconductor production system. <P>SOLUTION: The SiC film-formed glassy carbon material is obtained by forming SiC films deposited by a CVD (chemical vapor deposition) method on the surfaces of a glassy carbon base material having a planar or disk shape. In the SiC film-formed surfaces, the value of the ratio between the surface roughnesses RaL and RaS of two surfaces having large areas, RaL/RaS (wherein, RaL≥RaS) is 1.0 to 30, and also, the film thickness of the SiC films is 5 to 30 μm. In the SiC film-formed glassy carbon material with SiC films deposited by a CVD method on cylindrical glassy carbon base material surfaces, as for the surface roughnesses of the inner circumferential face and the outer circumferential face, provided that the larger one is defined as RaL, and the smaller one as RaS, the value of the ratio between the surface roughnesses, RaL/RaS is 1.0 to 30, and also, the film thickness of the SiC films is 5 to 30 μm. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oxidation resistance used in a high temperature and high purity atmosphere including members of a semiconductor manufacturing apparatus such as a susceptor, a process tube, a wafer boat or a gas or heat shielding plate. The present invention relates to a glassy carbon material coated with a SiC film, which is preferably used as the heat-resistant member.

[0002]

2. Description of the Related Art A glassy carbon material is superior to other carbon materials such as a graphite material in gas impermeability, wear resistance, corrosion resistance and surface smoothness. CV
A glassy carbon material coated with a SiC film having a high-purity and dense SiC film deposited by the D method to improve high-temperature oxidation resistance is a susceptor, a process tube, a wafer boat, a gas or heat shielding plate, etc. Is used as a member for the semiconductor manufacturing apparatus (Japanese Patent Laid-Open No. 3-217016, etc.).

However, when used as a member of a semiconductor manufacturing apparatus that repeatedly raises and lowers temperature such as rapid heating and rapid cooling, the SiC film is caused by the difference in thermal expansion coefficient between the glassy carbon material and the SiC film. There is a problem that cracks tend to occur, and the SiC film peels off from the starting point of the cracks.

In order to solve the above-mentioned problems, the applicant has deposited SiC on the glassy carbon substrate surface and
A SiC film-deposited glassy carbon material in which the vapor-phase thermal decomposition temperature for depositing the film is gradually raised from the initial film-forming process to the final film-forming process and kept at the vapor-phase thermal decomposition temperature in the final film-forming process for a predetermined time. Has been developed (Japanese Patent Laid-Open No. 2001-48682). Specifically, the vapor phase thermal decomposition temperature in the initial film formation process is set to 1
000 to 1200 ° C., the vapor phase pyrolysis temperature in the final film forming process is set to 1200 to 1700 ° C., and the temperature is controlled to 100 to 700 ° C. higher than in the initial film forming process. The heating rate to the process is controlled to 20 ° C./minute or less. By this method, the SiC film can be firmly adhered to the glassy carbon substrate surface.

However, along with the recent increase in the diameter of silicon wafers, it is necessary to increase the size of semiconductor manufacturing equipment, and the members formed from the SiC film-adhered glassy carbon material are also required to be increased in size. Due to the increase in the size of the member, S due to the difference in thermal expansion coefficient between the glassy carbon material and the SiC film
Cracking of the iC film is more likely to occur, and it has become difficult to sufficiently solve it even by the above technique.

[0006]

Therefore, the applicant of the present invention has found that in the SiC film-covered glassy carbon material coated with the SiC film by the CVD method, the Si of the SiC film by X-ray diffraction is used.
SiC film-coated glass having a C (111) crystal plane diffraction peak intensity of 10 kc.ps or less and a SiC (111) crystal plane diffraction peak intensity of 80% or more of the diffraction peak intensity of all crystal planes (hkl) A proposal and development (Japanese Patent Application No. 2000-285026) were made for a carbonaceous material and a manufacturing method thereof. This S
Although the iC film-covered glassy carbon material can be suitably used as a member for the above semiconductor manufacturing apparatus, it has been found that a new problem occurs in some applications in that it breaks during the temperature rising process.

As a result of a detailed study of this fracture phenomenon, the present inventors have found that in the case of a flat plate or a disk, two of the two faces having a large area out of a plurality of faces constituting the SiC film-deposited glassy carbon material. Fracture occurs when the ratio of surface roughness is out of a certain range, or fracture occurs when the ratio of surface roughness of the inner and outer peripheral surfaces is out of a certain range in the case of a cylindrical shape. I found out that.

The present invention has been completed based on the above findings, and its purpose is to rapidly heat a SiC film-adhered glassy carbonaceous material on which an SiC film is adhered by a CVD method, even when the size is increased. To provide a glassy carbon material coated with a SiC film, which has excellent thermal shock resistance and oxidation resistance capable of withstanding thermal shock caused by rapid cooling, and can be suitably used as various members for semiconductor manufacturing equipment. is there.

[0009]

In order to achieve the above-mentioned object, a glassy carbon material coated with a SiC film according to claim 1 of the present invention is a glass-like carbon substrate surface of a flat plate or a disk-shaped CVD. In the SiC film-deposited glassy carbon material coated with the SiC film deposited by the method, the surface roughness RaL, RaS (provided that RaL
≧ RaS), the ratio RaL / RaS is 1.0 to 30, and S
The structural feature is that the film thickness of the iC film is 5 to 30 μm.

Further, a glassy carbon material coated with a SiC film according to a second aspect of the present invention is a glassy carbon material coated with a SiC film, wherein a SiC film deposited by a CVD method is deposited on the surface of a cylindrical glassy carbon substrate. In the above, the larger one of the surface roughness of the inner peripheral surface and the outer peripheral surface is RaL, and the smaller one is RaS, the surface roughness ratio RaL / RaS is 1.0 to 30, and the thickness of the SiC film is The characteristic feature of the structure is that it is 5 to 30 μm.

A glassy carbon material coated with a SiC film according to claim 3 is characterized in that the glassy carbon substrate according to claim 1 has a penetrating portion such as a circle, a square, a rectangle or a triangle. The SiC film-deposited glassy carbon material according to item 4 is characterized in that, in claim 2, the glassy carbon substrate has a penetrating portion such as a circle, a square, a rectangle, or a triangle. The size of the penetrating part is not particularly specified, but for example, the size is 300 mm x 300 mm x 4 mm from a very small diameter of 0.3 mm.
A flat plate having a diameter of 220 mm and a large diameter having a through portion having a diameter of 220 mm can be given.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION There is no particular limitation on the glassy carbon material as a base material. For example, a thermosetting resin such as phenol-based, furan-based, or polyimide-based resin or a mixed resin thereof is cured and then molded. A product obtained by heating to a temperature of 800 ° C. or higher in an oxidizing atmosphere and calcining and carbonizing is used. However, the final heat treatment temperature needs to be higher than the temperature for forming the SiC film. In order to use as a member for a semiconductor manufacturing apparatus, it is required that the purity is as high as possible. For example, it is necessary to heat-treat to about 2000 ° C. in an atmosphere containing a halogen gas to achieve high purity. preferable.

To deposit a SiC film by the CVD method, a glassy carbon base material is set in a reaction chamber of a CVD apparatus, air in the system is exhausted and then heated to a predetermined temperature, and a raw material gas is fed. Then, the vapor phase thermal decomposition is performed to deposit SiC on the surface of the base material. The raw material gas contains Si atoms and C atoms in one molecule, such as trichloromethylsilane (CH ₃ SiCl ₃ ), dichloromethylsilane (CH ₃ SiHCl ₂ ), trichlorophenylsilane (C ₆ H ₅ SiC
l ₃ ), dichlorodimethylsilane ((CH ₃ ) ₂ SiCl ₂ ), chlorotrimethylsilane ((CH ₃ ) ₃ SiCl) and other halogenated organosilicon compounds are used and are fed into the reaction chamber together with hydrogen gas. Vapor phase reduction and thermal decomposition, or silicon compounds such as carbon tetrachloride and monosilane as Si sources, carbon compounds such as methane and propane as C sources, and hydrogen and argon gas as carrier gas into the reaction chamber. By feeding and causing a gas phase reaction, Si
It deposits C and deposits it on the surface of the substrate.

The glass-like carbon material coated with the SiC film of the present invention is
S deposited on the glassy carbon substrate surface by the above CVD method
The ratio of the surface roughness of the iC film adhered surface is set within a specific range. That is, when the glassy carbon base material has a flat plate shape or a circular disk shape, the surface roughness of two large surface areas (usually the front surface and the back surface) of the plurality of surfaces forming the SiC adhered surface is measured. Then, the value of the obtained surface roughness is Ra
L, a small value is RaS, and the value of the ratio RaL / RaS is defined to be 1.0 to 30.

When the glassy carbon substrate has a cylindrical shape, the surface roughness of the inner peripheral surface and the outer peripheral surface is measured, and a large value of the obtained surface roughness is RaL and a small value is RaS. , And the value of the ratio RaL / RaS is specified to be 1.0 to 30.

When the value of RaL / RaS exceeds 30, the difference in stress generated in the SiC film deposited on the flat plate-shaped or disk-shaped glassy carbon substrate surface increases, and the thermal shock resistance decreases.
Fracture easily occurs during the temperature rising / falling process. This phenomenon is S
Since the larger the iC deposition area is, the more remarkable it is, so two surfaces having a large SiC deposition area are targeted. Similarly, in the case of a cylindrical shape, the stress difference generated between the SiC films on the inner peripheral surface and the outer peripheral surface becomes large, so the thermal shock resistance decreases and breakage easily occurs during the temperature rising / cooling process.

The surface roughness is measured according to the center line average roughness described in JISB0601, and is, for example, Handy Surf E-30, an ultra-compact surface roughness measuring instrument manufactured by Tokyo Seimitsu Co., Ltd.
It can be measured by A.

The present invention defines the value of the surface roughness ratio RaL / RaS, but the values of RaL and RaS themselves are not particularly limited. This is because a predetermined surface roughness is often required depending on the application. For example, when fixing a Si wafer by vacuum chucking, the surface roughness Ra of the surface in contact with the Si wafer needs to be 1.0 μm or less, while it is used as a gas or heat shield plate in a CVD reactor. In this case, the product of the CVD reaction is also deposited on the SiC film adhered surface, and the surface roughness Ra is set to about 10 μm in order to prevent the deposit from peeling off and adhering to the object to be treated. It is necessary to improve the adhesion.

Further, depending on the members of the semiconductor manufacturing apparatus,
It may be convenient for the subsequent processing to preliminarily provide the glassy carbon substrate with a penetrating portion such as a circle, a square, a rectangle, or a triangle. In that case, in the case of the inventions of claims 3 and 4, As described above, a base material in which a penetrating portion such as a circle, a square, a rectangle, or a triangle is provided in advance on the glassy carbon base material is used.

In this case, S deposited on the glassy carbon substrate
The film thickness of the iC film is set to 5 to 30 μm. Film thickness is 5μ
If it is less than m, it is difficult to form a film having a uniform thickness.
There is a high possibility that there will be a portion that is not covered by the above or a portion where the film thickness is extremely thin, and sufficient oxidation resistance cannot be obtained. On the other hand, if the film thickness exceeds 30 μm, cracks and peeling are likely to occur after film formation.

The SiC film-adhered glassy carbon material of the present invention is
Manufactured by depositing a SiC film on the surface of a glassy carbon substrate and then treating the prescribed adherend, for example, the front and back surfaces of flat plates and discs, and the inner and outer peripheral surfaces of cylinders to the desired surface roughness. To be done. As a treatment method, it is possible to perform an appropriate method such as polishing with abrasive grains, shot blasting, laser processing, or water jet processing.

The present invention is based on S of glassy carbon material coated with SiC film.
The ratio of the surface roughness of the iC film is defined, not the ratio of the surface roughness of the glassy carbon material as the base material. However, when the film thickness of the SiC film is 30 μm or less, the surface roughness of the glassy carbon base material and the surface roughness of the SiC film are almost the same, so the ratio of the surface roughness of the glassy carbon base material is 1 By adjusting the range from 0 to 30,
The surface roughness ratio RaL / RaS of the SiC film is set to 1.0 to 30.
It becomes possible to control in the range of.

Therefore, if the surface of the glassy carbon base material is previously processed to have a predetermined surface roughness by the method such as polishing or shot blasting, the surface roughness ratio RaL / RaS of the adhered SiC film can be reduced. The value can be controlled in the range of 1.0 to 30. Further, it is possible to control the surface roughness of the glassy carbon by setting the surface of the mold to a predetermined roughness when molding the thermosetting resin which is the raw material of the glassy carbon material.

[0024]

EXAMPLES Examples of the present invention will be specifically described below in comparison with comparative examples.

Examples 1 to 6 and Comparative Examples 1 to 7 Phenol resin initial condensates prepared from phenol and formalin produced by vacuum distillation were poured into a polypropylene vat and deaerated under a reduced pressure of 10 Torr for 3 hours. Pre-cured in an electric oven at 80 ° C. Then, it was taken out from the molding die, heated to 180 ° C. at a heating rate of 10 ° C./hour, and held for 24 hours to be cured. This cured resin plate was sandwiched between high-purity graphite plates and placed in an electric furnace. The surrounding area was covered with graphite powder having a total ash content of less than 100 ppm and heated to 1000 ° C. at a heating rate of 2 ° C./hour. It was calcined and carbonized. Furthermore, it is transferred to a vacuum furnace that can replace the atmosphere, and while purifying gas of chlorine / argon (molar ratio: 5/95) at a rate of 5 liters / minute, the temperature is raised to 2000 ° C. for high purification treatment. Was applied.

From the glassy carbon plate thus obtained, a flat plate having a size of 300 × 300 mm and a thickness of 4 mm, and a plurality of discs having a diameter of 300 mm and a thickness of 4 mm were prepared as substrates. A through hole having a diameter of 100 mm was provided at the center of some of the base materials. The front and back surfaces of these flat plate-shaped and disk-shaped glassy carbon plates were processed to a predetermined surface roughness by shot blasting and set in the reaction chamber of the CVD device, and the air in the system was exhausted and then brought to a predetermined temperature. Heated to normal pressure
Hydrogen gas was fed under (0.1 MPa) to replace the atmosphere with hydrogen gas. Then, using methyltrichlorosilane as the source gas and hydrogen as the carrier gas, the concentration of methyltrichlorosilane in the mixed gas of methyltrichlorosilane / hydrogen gas and the reaction temperature were changed to deposit the SiC coating on the glassy carbon substrate surface. did.

Examples 7 to 9 and Comparative Examples 8 to 10 Phenol resin initial condensates prepared from phenol and formalin produced by vacuum distillation were poured into a cylinder with a core and deaerated under a reduced pressure of 10 Torr for 3 hours. Pre-cured in an electric oven at 80 ° C. Then, it is taken out of the mold and heated at a rate of 10 ° C./hour for 18
The temperature was raised to 0 ° C. and kept for 24 hours to cure. This cured resin molded body is put into an electric furnace, and the surrounding is covered with graphite powder having a total ash content of less than 100 ppm, and the temperature is raised to 1000 ° C at a heating rate of 2 ° C / hour.
Then, it was heated to and calcined. Further, it was transferred to a vacuum furnace capable of atmosphere replacement, and while supplying a purified gas of chlorine / argon (molar ratio: 5/95) at a rate of 5 liters / minute into the furnace, 200
The temperature was raised to 0 ° C. and a purification treatment was performed.

In this way, the inner diameter is 50 mm, the outer diameter is 55 mm,
A plurality of cylindrical glassy carbon substrates having a length of 200 mm were prepared. It should be noted that some base materials have a center (the length of the cylinder is 100
A through hole having a diameter of 30 mm was provided at a position (mm position). The inner peripheral surface and the outer peripheral surface of these base materials are barrel-polished to be processed into a predetermined surface roughness and set in a reaction chamber of a CVD device, air in the system is exhausted, and then heated to a predetermined temperature, and subjected to normal pressure. (0.1MPa)
Hydrogen gas was fed below to replace the atmosphere with hydrogen gas. Then, using methyltrichlorosilane as a source gas and hydrogen as a carrier gas, the concentration of methyltrichlorosilane in the mixed gas of methyltrichlorosilane / hydrogen gas and the reaction temperature are changed to deposit the SiC coating on the glassy carbon substrate surface. did.

The surface roughness of the front and back surfaces or the inner and outer peripheral surfaces of the glassy carbon material coated with the SiC film thus manufactured was measured by the following method. , The smaller one was designated as RaS. Also,
The thickness of the deposited SiC film was measured by the following method. The obtained results are shown in Tables 1 and 2.

Surface roughness: Measured in accordance with JIS B0601 using Handysurf E-30A, a micro surface roughness measuring instrument manufactured by Tokyo Seimitsu Co., Ltd., with a cutoff value of 0.8 mm and a measuring length of 4 mm. .

Thickness of SiC film: The sample was cut and the cross section was observed by SEM to measure the film thickness.

[0032]

[Table 1]

[0033]

[Table 2]

Next, these SiC film-adhered glassy carbon materials were subjected to a thermal shock test and an oxidation test by the following methods, and the results are shown in Table 3. Note that Comparative Example 3 and Comparative Example 6 in which cracks and peeling were observed after forming the SiC film
This test has not been carried out.

Thermal shock test: The sample was placed in an electric furnace heated to 1200 ° C. and held for 10 minutes, then taken out of the furnace, cooled to 200 ° C. at once, and then put into an electric furnace heated to 1200 ° C. again. The heat cycle test of holding for 10 minutes for 10 minutes was repeated to determine the number of tests when the SiC coating was cracked or peeled or ruptured. The heat cycle test was performed 50 times, and in the examples, the state of the SiC coating after the heat cycle test was repeated 50 times was observed. Further, this test was not conducted for Comparative Example 3 and Comparative Example 6 in which cracks and peeling were observed after forming the SiC film.

Oxidation test; 100 in the atmosphere
Weight was measured after holding at a temperature of 0 ° C. for 24 hours, and the weight reduction rate was calculated.

[0037]

[Table 3] Note) * 1 No abnormality in the SiC film, * 2 Crack, peeling, breakage, etc. occurred in the SiC film

From the results of Tables 1 to 3, Si of Examples 1 to 9 was obtained.
With respect to the glassy carbonaceous material coated with the C film, no abnormality was found in the SiC film even after the thermal shock test of rapid heating and rapid cooling from 200 ° C. to 1200 ° C. was repeated 50 times. On the other hand, Comparative Examples 1, 2, 4, in which the value of RaL / RaS exceeds 30,
It can be seen that the SiC film-coated glassy carbonaceous materials of 5, 8, 9, and 10 are extremely inferior in thermal shock resistance.

The surface roughness ratio RaL / RaS is 30.
Even in the following cases, in Comparative Examples 3 and 6 in which the film thickness of the SiC film exceeds 30 μm, cracks and peeling occurred after the film formation of the SiC film, while the comparative examples in which the film thickness of the SiC film was 5 μm or less. In No. 7, it was confirmed that the SiC film had color spots, the substrate was partially exposed, and the oxidation resistance and thermal shock resistance were inferior.

[0040]

As described above, according to the SiC film-deposited glassy carbon material of the present invention, the ratio of the surface roughness (RaL / RaS) of two surfaces having a large adhered area, to which the SiC film is adhered, is measured. ) Is specified as 1.0 to 30 and the thickness of the SiC film is set to 5
By specifying 30 μm, it has excellent thermal shock resistance and oxidation resistance, and heat-resistant members for various heat treatments used in semiconductor manufacturing such as guide rings, susceptors, liner tubes, process tubes, wafer boats, and single crystal pulling equipment. Can be preferably used as.

Claims (4)

[Claims] 1. An S film obtained by depositing a SiC film deposited by a CVD method on the surface of a flat plate-shaped or disk-shaped glassy carbon substrate.
In the iC film-deposited glassy carbon material, the ratio RaL / RaS of the surface roughnesses RaL and RaS (however, RaL ≧ RaS) of two surfaces having a large area among the SiC film-deposited surfaces has a value RaL / RaS of 1.0 to 30.
And a SiC film-coated glassy carbonaceous material, characterized in that the film thickness of the SiC film is 5 to 30 μm. 2. CVD on a cylindrical glassy carbon substrate surface
In the SiC film-deposited glassy carbon material coated with the SiC film deposited by the method, the larger surface roughness of the inner peripheral surface and the outer peripheral surface is RaL, and the smaller surface roughness is RaS. A glassy carbon material coated with a SiC film, wherein the value of / RaS is 1.0 to 30 and the film thickness of the SiC film is 5 to 30 μm. 3. The SiC film-adhered glassy carbon material according to claim 1, wherein the glassy carbon substrate has a penetrating portion such as a circle, a square, a rectangle, and a triangle. 4. The SiC film-adhered glassy carbon material according to claim 2, wherein the glassy carbon substrate has a penetrating portion such as a circle, a square, a rectangle, and a triangle.