Sintered silicon carbide, method for producing the same, and method for producing silicon carbide grains

Abstract

To provide a silicon carbide sintered compact having a low nitrogen content and a high density, and to provide silicon carbide particles suitable for producing the same.SOLUTION: A silicon carbide powder is produced by using a novolak type phenol resin as a carbon source, the produced silicon carbide powder is heated in an oxygen-containing atmosphere to perform a nitrogen-lowering treatment, the silicon carbide powder is granulated into silicon carbide granules by using the novolak type phenol resin, and the granulated silicon carbide granules are sintered into a silicon carbide sintered compact. Preferably, the nitrogen content of the sintered body is 20ppm or less, and the bulk density is 3. 10g / cm3 or more.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a silicon carbide sintered body and a method for producing the same, as well as a method for producing silicon carbide granules suitable for producing the silicon carbide sintered body. [Background technology]

[0002] Silicon carbide sintered bodies are widely used as heat-resistant components and are suitable for semiconductor devices. When silicon carbide sintered bodies are used, for example, as susceptors (wafer support members) in semiconductor manufacturing equipment, it is necessary to keep the nitrogen content of the silicon carbide sintered bodies low to prevent the incorporation of nitrogen, which can act as a dopant into the wafer. However, there have been few studies on reducing the nitrogen content of silicon carbide sintered bodies.

[0003] Patent Document 1 describes, in Example 1, that tetraethoxysilane, maleic acid as a catalyst, and liquid resol-type xylene resin were mixed to form a candy-like mixture, which was then thermally cured at 70°C to form a resinous solid, which was then carbonized at 900°C under vacuum to form a carbide, which was then heated to and maintained at 1900°C under an argon atmosphere to form silicon carbide powder, and that the nitrogen amount (nitrogen content) of this silicon carbide powder was less than 40 ppm. Furthermore, it is described that this silicon carbide powder was placed in a hot press, and the temperature was gradually increased from room temperature to 1500°C under vacuum conditions and maintained at that temperature, and then pressurized, and the temperature was increased to 2300°C in an argon atmosphere and maintained at that temperature, and then cooled and maintained at 1950°C under vacuum conditions in a heat treatment furnace to produce a silicon carbide sintered body. However, the nitrogen content and density of this silicon carbide sintered body are not described. In addition, paragraph 0005 states that the nitrogen content of the silicon carbide sintered body is 50 ppm or less, and paragraph 0048 states that the density of the silicon carbide sintered body is 3.0 g / cm 3 Although it is stated that the above values ​​are preferable, the numerical values ​​in Example 1 are unknown. In addition, in Comparative Example 1, silicon carbide powder was produced in the same manner as in Example 1, except that resol-type xylene resin was replaced with resol-type phenolic resin, and the nitrogen content of this silicon carbide powder was 500 ppm or more.It is also described that a silicon carbide sintered body was produced using this silicon carbide powder, but the nitrogen content and density of this silicon carbide sintered body are not described.

[0004] In Patent Document 2, as an example, it is described that a raw material composition is prepared by mixing and kneading silicon dioxide powder with a novolac-type phenolic resin, and this raw material composition is poured into an alumina container, heated to 400°C in an air atmosphere and maintained at that temperature, and then heated to 800°C in a nitrogen atmosphere and maintained at that temperature, and then cooled to obtain a carbonized molded body with a bulk density of 1.60 g / cm3. Furthermore, a rectangular parallelepiped compact was cut out from this compact, fired at 1700°C in an argon atmosphere, and then cooled to obtain a compact with fine pores and a bulk density of 0.52 g / cm. 3 It is also described that a porous silicon carbide body consisting of β-type crystals was obtained. However, the nitrogen content of the silicon carbide porous body is not described.

[0005] Patent Document 3 describes, in Example 1, that ethyl silicate, a liquid resol-type phenolic resin, and an aqueous solution of p-toluenesulfonic acid as a catalyst were mixed, cured, and dried to form a resinous solid, which was then carbonized at 900°C in a nitrogen atmosphere, and the resulting carbide was heated to and maintained at 1900°C in an argon atmosphere to obtain a β-type silicon carbide-carbon mixed powder. However, the amount of nitrogen in this mixed powder is not described. Furthermore, the document describes that this mixed powder is blended with novolac-type phenolic resin and DBP as binders, to which stearic acid and ethanol are added and mixed, and then granulated using an extruder and dried. The resulting mixture is molded in a mold using an injection molding machine and thermoset, and the resulting molded body is placed in a furnace, heated to 900°C in an argon atmosphere and maintained at that temperature, then cooled in the furnace. The carbonized molded body is then brought into contact with high-purity silicon molten at 1500°C in an argon atmosphere and subjected to reactive sintering to obtain a β-type silicon carbide sintered body. However, the nitrogen content and density of this β-type silicon carbide sintered body are not described. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 4700835 [Patent Document 2] Japanese Patent Application Publication No. 3-122065 [Patent Document 3] Patent No. 3174622 Summary of the Invention [Problem to be solved by the invention]

[0007] Therefore, an object of the present invention is to provide a silicon carbide sintered body with a low nitrogen content and a high density, and silicon carbide particles suitable for producing the same. [Means for solving the problem]

[0008] [1] Silicon carbide powder is produced using a novolac phenolic resin as a carbon source; The silicon carbide powder thus produced is granulated into silicon carbide granules using a novolac-type phenolic resin.

[0009] [2] A method for reducing nitrogen in silicon carbide powder, in which silicon carbide powder is heated in an oxygen-containing atmosphere to reduce the amount of nitrogen.

[0010] [3] producing silicon carbide powder using a novolac-type phenolic resin as a carbon source; The resulting silicon carbide powder is heated in an oxygen-containing atmosphere to reduce the amount of nitrogen; A method for producing silicon carbide granules by granulating silicon carbide powder with a reduced nitrogen content into silicon carbide granules using a novolac-type phenolic resin or a resol-type phenolic resin.

[0011] [4] producing silicon carbide powder using a novolac-type phenolic resin as a carbon source; The resulting silicon carbide powder is granulated into silicon carbide particles using a novolac-type phenolic resin; A method for producing a silicon carbide sintered body, comprising sintering granulated silicon carbide particles into a silicon carbide sintered body.

[0012] [5] producing silicon carbide powder using a novolac-type phenolic resin as a carbon source; The resulting silicon carbide powder is heated in an oxygen-containing atmosphere to reduce the amount of nitrogen; The silicon carbide powder with reduced nitrogen content is granulated into silicon carbide particles using a novolac-type phenolic resin, A method for producing a silicon carbide sintered body, comprising sintering granulated silicon carbide particles into a silicon carbide sintered body.

[0013] [6] producing silicon carbide powder using a novolac-type phenolic resin as a carbon source; The resulting silicon carbide powder is heated in an oxygen-containing atmosphere to reduce the amount of nitrogen; The silicon carbide powder with reduced nitrogen content is granulated into silicon carbide particles using a resol-type phenolic resin, A method for producing a silicon carbide sintered body, comprising sintering granulated silicon carbide particles into a silicon carbide sintered body.

[0014] [7] The method for producing a silicon carbide sintered body according to [4], wherein the amount of nitrogen in the silicon carbide sintered body is 40 ppm or less.

[0015] [8] The method for producing a silicon carbide sintered body according to [5], wherein the amount of nitrogen in the silicon carbide sintered body is 20 ppm or less.

[0016] [9] The heating temperature in an oxygen-containing atmosphere is 300 to 800 ° C., The density of sintered silicon carbide is 3.00 g / cm 3 The method for producing a silicon carbide sintered body according to [5] or [6] above.

[0017]

[10] The heating temperature in an oxygen-containing atmosphere is 350 to 650 ° C., The density of sintered silicon carbide is 3.10 g / cm 3 The method for producing a silicon carbide sintered body according to [5] or [6] above.

[0018]

[11] Nitrogen content is 40 ppm or less and density is 3.10 g / cm 3 The silicon carbide sintered body is as described above.

[0019]

[12] A semiconductor manufacturing equipment member using the silicon carbide sintered body according to

[11] above.

[0020]

[13] A susceptor using the silicon carbide sintered body according to

[11] above.

[0021] (action) By using a novolac-type phenolic resin as the carbon source to produce silicon carbide powder, the nitrogen content of the silicon carbide powder can be kept low. The produced silicon carbide powder is heated in an oxygen-containing atmosphere to reduce the nitrogen content of the silicon carbide powder. The heating temperature is preferably 300 to 800°C, more preferably 350 to 650°C, since this makes it easy to reduce the nitrogen content and prevents the oxygen content from increasing. By granulating the nitrogen-reduced silicon carbide powder into silicon carbide granules using a novolac-type phenolic resin, the nitrogen content of the silicon carbide granules can be kept low. These effects allow the amount of nitrogen to be reduced while maintaining the density of the sintered body. [Effects of the Invention]

[0022] According to the present invention, it is possible to provide a silicon carbide sintered body having a low nitrogen content and a high density, and silicon carbide particles suitable for producing the same. DETAILED DESCRIPTION OF THE INVENTION

[0023] raw material (1) Silicon source The silicon source may be in liquid or solid form, but preferably contains a liquid silicon source. The liquid silicon source is not particularly limited, but examples thereof include alkoxysilane compounds, ethyl silicate, and alkoxysilane oligomers. The solid silicon source is not particularly limited, but examples thereof include SiO, silica sol, silicon oxide such as silicon dioxide, and metallic Si. (2) Carbon source Novolac-type phenolic resin is used as the carbon source. This is because novolac-type phenolic resin is synthesized using an acidic catalyst, which does not increase the nitrogen content. In contrast, resol-type phenolic resin uses alkaline catalysts such as amine compounds and alkali metal compounds, making it difficult to suppress the increase in nitrogen content due to the amine compounds and the increase in impurity elements due to the alkali metal compounds. The novolac phenolic resin is preferably a high-purity resin having an impurity element content of 20 ppm or less (more preferably 5 ppm or less, and even more preferably 0.5 ppm or less). (The impurity element refers to an element belonging to Groups 1 to 16 of the Periodic Table of the 1989 IUPAC Inorganic Nomenclature Revised Edition and having an atomic number of 3 or more (excluding atomic numbers 6 to 8 and 14) (the same applies hereinafter).) The novolac type phenolic resin may be in a liquid or solid state, but in the case of a solid state, it is desirable to use it after dissolving it in an appropriate solvent. (3) Catalysts and reactants A catalyst may be added. The catalyst is not particularly limited, but examples thereof include maleic acid, p-toluenesulfonic acid, acetic acid, acrylic acid, oxalic acid, malonic acid, and succinic acid. Pure water may be added as a reactant. When ethyl silicate or alkoxysilane is used as the silicon source, adding pure water promotes hydrolysis and polymerization, and the reaction proceeds.

[0024] Silicon carbide powder production The method for producing silicon carbide powder is not particularly limited, but an example thereof is a method carried out by the following steps (1) to (4). (1) Synthesis and drying process: A silicon source, a novolac phenolic resin, a catalyst, and water are mixed to form a liquid (including a viscous) mixture, which is then reacted and dried to form a solid. (2) Carbonization step: The solid material is heated to 500 to 1000°C in a non-oxidizing atmosphere to form a carbonized material. (3) Calcination step: The carbide is heated to 1700 to 2000° C. in a non-oxidizing atmosphere to form silicon carbide coarse particles. It is preferable that the nitrogen content of the silicon carbide coarse particles is 10 ppm or less. (4) Pulverization step: The silicon carbide coarse particles are pulverized to produce silicon carbide powder. The pulverization method is not particularly limited, but examples include pulverization using a dry jet mill. Even when pulverizing using a dry jet mill, it is preferable to keep the nitrogen content of the silicon carbide powder at 100 ppm or less. In this case, the particle size of the pulverized silicon carbide powder is preferably an average particle size (D50) of about 1 to 4 μm. This is because if the average particle size is too large, it becomes difficult to increase the density of the silicon carbide sintered body after sintering.

[0025] <c>Low nitrogen treatment The silicon carbide powder thus produced is heated in an oxygen-containing atmosphere in order to reduce the nitrogen contained in the silicon carbide powder. The heating temperature for the nitrogen reduction treatment is not particularly limited, but is preferably 300 to 800°C, and more preferably 350 to 650°C. If the temperature is below 300°C, the nitrogen content is unlikely to decrease. If the temperature exceeds 800°C, the oxygen content is likely to increase, which may make the material unsuitable for sintering (density may decrease). An example of an oxygen-containing atmosphere is air.

[0026] <d>Granulation The heat-treated powder is granulated with novolac phenolic resin or resol phenolic resin. The purpose of granulation is to improve handling, to leave the carbon uniformly by heating, and to utilize the effect of carbon as a sintering aid. Novolac-type phenolic resins are preferred because they do not increase the amount of nitrogen. However, when using novolac-type phenolic resins as a carbon source and carrying out the above-mentioned steps, the amount of nitrogen can be reduced by these actions, and therefore it is acceptable to use resol-type phenolic resins for granulation. The novolac type phenolic resin or resol type phenolic resin is preferably a high purity resin having an impurity element content of 20 ppm or less (more preferably 5 ppm or less, and even more preferably 0.5 ppm or less). The granulation method is not particularly limited, but examples include spray granulation (spray drying), fluidized bed granulation, and tumbling granulation. The silicon carbide granules after granulation preferably have an average particle size (D50) of about 30 to 150 μm. In this case, granulation by spray granulation (spray drying) allows the carbon to remain uniformly and silicon carbide granules with good handleability to be produced.

[0027] <e>Sintering The sintering method is not particularly limited, but examples include a hot pressing method, a reaction sintering method, etc. In this case, the hot pressing method is preferred because it can improve the density of the silicon carbide sintered body after sintering. The maximum temperature of the hot press is not particularly limited, but can be 2300 to 2400°C, for example. The pressure of the hot press is not particularly limited, but can be exemplified as 20 to 50 MPa.

[0028] <f>Purpose The uses of the silicon carbide sintered body of the present invention are not particularly limited, but examples include semiconductor manufacturing equipment components such as susceptors (wafer support members), susceptor covers (members that protect wafer support members), heaters, rings, electrodes, sputtering targets, etc. Due to the low nitrogen content, the silicon carbide sintered body is particularly suitable for susceptors. [Example]

[0029] Next, examples embodying the present invention will be described in comparison with comparative examples. Note that the materials, quantities, and conditions of each part in the examples are merely examples and can be changed as appropriate without departing from the scope of the invention. Examples 1 to 5 and Comparative Example 1 shown in Table 1 were carried out.

[0030] [Table 1]

[0031] [Example 1] (1)Synthesis / drying process As the silicon source, which is a raw material, a liquid ethyl silicate oligomer (trade name: Ethyl Silicate 40, manufactured by Colcoat Co., Ltd., SiO2 content: 40 mass%) was used. As a carbon source, a solid high-purity novolac type phenolic resin (trade name: PR56431, manufactured by Sumitomo Bakelite Co., Ltd.) was used. A liquid maleic acid aqueous solution (produced by Nippon Shokubai Co., Ltd., which was prepared by hydrolyzing and dissolving maleic anhydride in pure water) was used as the catalyst. 24% by mass of ethanol and 16% by mass of novolac phenolic resin were placed in a container and stirred to dissolve the novolac phenolic resin in the ethanol, and then 40% and 51% by mass of ethyl silicate, 8% by mass of an aqueous maleic acid solution, and 1% by mass of pure water were added and mixed to form a viscous mixture. The mixture was gradually heated from room temperature to 200°C, reacted and dried to obtain a lumpy solid.

[0032] (2) Carbonization process This solid was placed in a continuous atmosphere furnace and heated at 900°C for 2 hours in an argon atmosphere to obtain a carbide mass.

[0033] (3) Firing process This carbide was placed in a vacuum furnace, heated to 1900°C in an argon atmosphere, and held there for 4 hours to obtain silicon carbide coarse particles with particle sizes of approximately several tens of micrometers. The crystal structure of the silicon carbide coarse particles was measured using an X-ray diffractometer (Rigaku Corporation, trade name: Ultima IV), and was found to be 100% β-SiC. The nitrogen content of the silicon carbide coarse particles was measured using an oxygen / nitrogen analyzer (manufactured by LECO Corporation, trade name: TC-600) and was found to be 10 ppm or less.

[0034] (4) Crushing process The silicon carbide coarse particles were pulverized in a dry jet mill to produce silicon carbide powder. The particle size of the produced silicon carbide powder was measured using a particle size distribution analyzer (product name: LS-13-320, manufactured by Beckman Coulter), and the average particle size (D50) was found to be 2 to 3 μm. The nitrogen content of the produced silicon carbide powder was measured on three samples using the TC-600, and the average was 43 ppm. The reason for this increase in nitrogen content due to pulverization using a dry jet mill is thought to be that, since pulverization is carried out in air, nitrogen in the air is incorporated into the silicon carbide during pulverization.

[0035] (5) Low-nitrogen treatment process The silicon carbide powder produced as described above was placed in a quartz container and heated at 400° C. for 2 hours in an oxygen-containing atmosphere (air atmosphere) to reduce the amount of nitrogen. The nitrogen content of the silicon carbide powder after the nitrogen reduction treatment step was measured for three samples using the TC-600, and the average was 26 ppm. At this time, it was confirmed that the particle size of the silicon carbide powder after the nitrogen reduction treatment step had an average particle size (D50) of 2 to 3 μm, and there was almost no change before and after the nitrogen reduction treatment step.

[0036] (6) Granulation process A container was charged with 55 mass % of silicon carbide powder with a reduced nitrogen content, 5 mass % of novolac phenolic resin as an auxiliary agent, and 40 mass % of ethanol as a dispersion medium, and mixed to form a liquid mixture. This mixture was sprayed and granulated using a spray dryer, and then passed through a sieve with 200 μm openings to obtain granulated silicon carbide particles (average particle size: 80 μm).

[0037] (7) Sintering process The granulated silicon carbide particles were placed in a graphite mold and sandwiched between graphite punches. Using a hot press, the temperature was raised to 1800°C under vacuum conditions, pressurized at 40 MPa, and then heated to a maximum temperature of 2300°C in an argon atmosphere and held for 8 hours (hot press), yielding a silicon carbide sintered body. The nitrogen content of this silicon carbide sintered body was measured for three samples using a secondary ion mass spectrometer (hereinafter referred to as SIMS), and the average was 9 ppm. The density of this silicon carbide sintered body was measured by the Archimedes method and found to be 3.14 g / cm 3 It was.

[0038] [Example 2] In Example 1, except that the heating temperature in the (5) nitrogen reduction treatment step was changed from 400°C to 600°C, silicon carbide powder was produced in the same manner as in (1) to (4) of Example 1, the nitrogen content was reduced in the same manner as in (5), granulation was performed in the same manner as in (6), and silicon carbide sintered body was obtained in the same manner as in (7). As in Example 1, (4) the nitrogen content of the silicon carbide powder after pulverization, (5) the nitrogen content of the silicon carbide powder after the nitrogen reduction treatment step, and (7) the nitrogen content and density of the sintered body after sintering are shown in Table 1.

[0039] [Example 3] In Example 1, except that the heating temperature in the (5) nitrogen reduction treatment step was changed from 400°C to 800°C, silicon carbide powder was produced in the same manner as in (1) to (4), the nitrogen content was reduced in the same manner as in (5), granulation was performed in the same manner as in (6), and silicon carbide sintered body was obtained in the same manner as in (7). As in Examples 1 and 2, the nitrogen content and density are shown in Table 1. (7) The density of the sintered body after sintering was 3.02 g / cm 3 The reason for the low value is thought to be that (5) the heating temperature was set to 800°C in the low-nitridation treatment process, which resulted in oxygen being absorbed into the silicon carbide powder from the oxygen-containing atmosphere.

[0040] [Example 4] In Example 1, silicon carbide powder was produced in the same manner as in (1) to (4) of Example 1, except that the (5) nitrogen reduction treatment step was not performed, the produced silicon carbide powder was granulated in the same manner as in (6), and a silicon carbide sintered body was obtained in the same manner as in (7). As in Examples 1 and 2, the nitrogen content and density are shown in Table 1.

[0041] [Example 5] In Example 1, except that the novolac-type phenolic resin was changed to a resol-type phenolic resin in the granulation step (6), silicon carbide powder was produced in the same manner as in (1) to (4), the nitrogen content was reduced in the same manner as in (5), granulation was performed in the same manner as in (6), and a silicon carbide sintered body was obtained in the same manner as in (7). As in Examples 1 and 2, the nitrogen content and density are shown in Table 1. (6) Because a resol-type phenolic resin was used in the granulation process, (5) the nitrogen content was reduced to 26 ppm in the nitrogen reduction treatment, (7) the nitrogen content of the sintered body after sintering was 35 ppm. In this case, SR101, a product name manufactured by Air Water Performance Chemicals Inc., was used as the resol-type phenolic resin.

[0042] [Comparative Example 1] In Example 4, silicon carbide powder was produced in the same manner as in (1) to (4), granulated in the same manner as in (6), and silicon carbide sintered body was obtained in the same manner as in (7), except that in (1) synthesis and drying step, novolac type phenolic resin was changed to resol type phenolic resin, and in (6) granulation step, novolac type phenolic resin was changed to resol type phenolic resin. In this case, the resol type phenolic resin used in (1) synthesis and drying step and (6) granulation step was SR101, a product name manufactured by Air Water Performance Chemicals Inc. As in Examples 1 and 2, the nitrogen content and density are shown in Table 1.

[0043] The silicon carbide sintered body of Comparative Example 1 has a density of 3.00 g / cm 3 However, the nitrogen content is high at 680 ppm. In contrast, the silicon carbide sintered bodies of Examples 1 to 5 have nitrogen contents of 40 ppm or less and densities of 3.00 g / cm 3 That's all. Density is 3.10g / cm 3 Examples 1, 2, 4, and 5 were superior in that the nitrogen content was 30 ppm or less, and Examples 1, 2, and 4 were superior in that the nitrogen content was 20 ppm or less, and Examples 1, 2, and 3 were superior in that the nitrogen content was 3.10 g / cm 3 In view of the above, Examples 1 and 2, which satisfy the nitrogen amount of 15 ppm or less, are most preferable.

[0044] The present invention is not limited to the above-described embodiments, and can be embodied by making appropriate modifications without departing from the spirit of the invention.< / f> < / e> < / d> < / c>

Claims

1. producing silicon carbide powder using a novolac-type phenolic resin as a carbon source; The silicon carbide powder thus produced is granulated into silicon carbide granules using a novolac-type phenolic resin.

2. A method for reducing nitrogen in silicon carbide powder, in which the silicon carbide powder is heated in an oxygen-containing atmosphere to reduce the amount of nitrogen.

3. producing silicon carbide powder using a novolac-type phenolic resin as a carbon source; The resulting silicon carbide powder is heated in an oxygen-containing atmosphere to reduce the amount of nitrogen; A method for producing silicon carbide granules, comprising granulating silicon carbide powder having a reduced nitrogen content into silicon carbide granules using a novolac-type phenolic resin or a resol-type phenolic resin.

4. producing silicon carbide powder using a novolac-type phenolic resin as a carbon source; The resulting silicon carbide powder is granulated into silicon carbide particles using a novolac-type phenolic resin; A method for producing a silicon carbide sintered body, comprising sintering granulated silicon carbide particles into a silicon carbide sintered body.

5. producing silicon carbide powder using a novolac-type phenolic resin as a carbon source; The resulting silicon carbide powder is heated in an oxygen-containing atmosphere to reduce the amount of nitrogen; The silicon carbide powder with reduced nitrogen content is granulated into silicon carbide particles using a novolac-type phenolic resin, A method for producing a silicon carbide sintered body, comprising sintering granulated silicon carbide particles into a silicon carbide sintered body.

6. producing silicon carbide powder using a novolac-type phenolic resin as a carbon source; The resulting silicon carbide powder is heated in an oxygen-containing atmosphere to reduce the amount of nitrogen; The silicon carbide powder with reduced nitrogen content is granulated into silicon carbide particles using a resol-type phenolic resin, A method for producing a silicon carbide sintered body, comprising sintering granulated silicon carbide particles into a silicon carbide sintered body.

7. 5. The method for producing a silicon carbide sintered body according to claim 4, wherein the amount of nitrogen in the silicon carbide sintered body is 40 ppm or less.

8. 6. The method for producing a silicon carbide sintered body according to claim 5, wherein the amount of nitrogen in the silicon carbide sintered body is 20 ppm or less.

9. The heating temperature in an oxygen-containing atmosphere is 300 to 800°C, The density of the silicon carbide sintered body is 3.00 g / cm ３ The method for producing a silicon carbide sintered body according to claim 5 or 6.

10. The heating temperature in an oxygen-containing atmosphere is 350 to 650°C, The density of the silicon carbide sintered body is 3.10 g / cm ３ The method for producing a silicon carbide sintered body according to claim 5 or 6.

11. The nitrogen content is 40 ppm or less, and the density is 3.10 g / cm ３ The silicon carbide sintered body is as described above.

12. A member for semiconductor manufacturing equipment, which uses the silicon carbide sintered body according to claim 11.

13. A susceptor using the silicon carbide sintered body according to claim 11.

Images