JP2012126604A - METHOD FOR PRODUCING SiC MEMBER FOR SEMICONDUCTOR PRODUCTION PROCESS - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing an SiC member for a semiconductor production process, by a cleaning method with an acid, which is low-cost and has a small environmental load, relative to a low-cost molding method such as extrusion molding.SOLUTION: After drying a molded body in aqueous-system extrusion molding, a degreasing step by heat treatment at a temperature of 350-450°C in an inert gas atmosphere and an acid cleaning step are carried out.

Description

  The present invention relates to a method for manufacturing a SiC processing jig used in a heat treatment process for semiconductor manufacturing.

  A SiC jig for a semiconductor manufacturing process is required to have a high purity in order to prevent contamination by impurity elements from the jig to a semiconductor product during semiconductor manufacturing. For this reason, when manufacturing a jig, a high-purity raw material is used, and work is performed with great care so that impurities are not mixed during the manufacturing. Usually, a method for avoiding metal contamination as much as possible is selected as the jig manufacturing process.

  As a method for forming the jig, casting molding, extrusion molding, isostatic pressing, injection molding, or the like is used. Among these, casting molding and isostatic pressing have the advantage that there is no contact with metal parts during molding and the molded body is less contaminated with metal, but there are problems in molding tact and cost. On the other hand, extrusion molding can be used to improve molding tact and reduce costs in principle, but it is a method to obtain a molded body by applying high pressure when passing a kneaded material of ceramics as a raw material through an extrusion die. It is difficult to avoid contact between the kneaded material and a pressure component such as a metal screw. Further, since SiC is a very hard substance, there is a possibility that a non-negligible amount of metal may be mixed in contact with the pressurized part.

  In such a case, in general, a SiC jig for semiconductor manufacturing process (hereinafter referred to as “a jig for semiconductor manufacturing process”) is produced by a method of decomposing and volatilizing impurity elements in the fired body formed by firing process by flowing HCL gas after firing the molded body. (Referred to as Patent Document 1).

  However, in the case of this method, environmental measures equipment such as HCL gas introduction equipment and exhaust gas treatment equipment is necessary for the firing furnace, and since the treatment is performed at a high temperature exceeding 2000 ° C., there is a concern about high cost of the product. It was a material. Further, since the processing equipment continuously discharges the processing gas without reusing it, the load on the environment is high, and the tendency to dislike the processing equipment has increased. In particular, in the case of the extrusion method, the degree of metal contamination is high in principle. For this reason, a method has been proposed in which a molded body formed by extrusion molding is immersed in an aqueous solution such as an acid to elute and remove the metal or metal oxide (for example, see Patent Document 2).

Japanese Patent No. 3543529 Japanese Patent No. 2867623

  However, Patent Document 2 does not include specific examples of ceramic materials or specific descriptions regarding purity in a product or a manufacturing process. Further, if the calcination process of Patent Document 2 is applied as it is, specifically, when the conditions of 600 ° C. to 800 ° C. are applied, the temperature is too high, so that metal elements such as Fe diffuse into the SiC, and the cleaning process also The product could not be manufactured because it could not be highly purified.

  In view of the above problems, the present invention provides a method for producing a SiC member for a semiconductor manufacturing process, which uses an acid cleaning method that is also low in cost and has a low environmental impact with respect to a low-cost molding method such as extrusion molding. To do.

The present invention
A kneading step of kneading SiC powder, an organic binder mainly composed of a water-soluble resin, a surface treatment agent, and water to obtain a kneaded product;
A molding step of obtaining a molded body by extruding the kneaded product;
A drying step of drying the molded body;
A degreasing step of heat-treating the molded body after the drying step in an inert gas atmosphere at a temperature of 350 to 450 ° C;
An acid washing step of washing the molded body after the degreasing step with an acid;
The manufacturing method of the SiC member for semiconductor manufacturing processes which manufactures the SiC member for semiconductor manufacturing processes by having.

  The acid may be a mixed acid of hydrochloric acid, nitric acid and water, hydrofluoric acid or hydrochloric acid.

  The manufacturing method includes a kneading step of kneading at a temperature of 5 to 20 ° C. to obtain a kneaded product, a molding step for obtaining a molded product by extruding the kneaded product at a temperature of 5 to 20 ° C., and 50 And a drying step of drying at a temperature of at least ° C.

  The acid may be a mixed acid of hydrochloric acid, nitric acid and water at 50 to 100 ° C., hydrochloric acid at 50 to 100 ° C. or hydrofluoric acid at normal temperature.

  The inert gas may be nitrogen.

  The average particle diameter of the SiC powder may be 1 to 10 μm, and the proportion of the SiC powder may be 66 to 78 wt% with respect to the total amount of the kneaded material.

  As the water-soluble resin, methylcellulose and polyethylene glycol having a molecular weight of 250 to 550 may be included.

  As said water-soluble resin, methylcellulose and polyethyleneglycol are included, The mass ratio with respect to methylcellulose of polyethyleneglycol is 0.67-1.5, and it may be 15-25 wt% aqueous solution with methylcellulose and water.

  According to the present invention, an extremely high-purity SiC member suitable for a semiconductor manufacturing process can be manufactured by a method with low cost and low environmental load.

FIG. 1 is a process diagram of a manufacturing process of an SiC member for a semiconductor manufacturing process according to the present invention.

  FIG. 1 shows steps of a manufacturing process of a SiC member for a semiconductor manufacturing process according to the present invention. The embodiment of the present invention will be described with reference to FIG. 1 focusing on the main part, that is, the acid cleaning step.

<Kneading process>
First, SiC powder, a water-soluble resin, and water are prepared as materials to be kneaded (hereinafter also referred to as kneaded materials). Such extrusion molding using water-containing raw materials (hereinafter, also referred to as water-based extrusion molding) is more effective in removing gases and harmful substances in the firing process than resin-based extrusion molding including thermoplastic resins such as polyethylene, polypropylene, and polystyrene. Since it does not occur, the load on the environmental countermeasure equipment can be reduced.

  The ratio of the SiC powder to the total amount of the kneaded material is preferably 66 to 78 wt%. Furthermore, 68-74.5 wt% is more preferable. If it is less than 66 wt%, the strength of the molded product will be insufficient in the subsequent acid cleaning step, making it difficult to maintain the shape. Further, the porosity of the molded body (hereinafter also referred to as a fired body) after the firing process to be performed later becomes high and the mechanical strength is insufficient, and the stress generated by the expansion of Si (silicon) in the metal silicon impregnation process. It cannot withstand, and there is a risk of cracking after impregnation with Si, resulting in failure. If it exceeds 74.5 wt%, the amount of wear of Fe or the like increases and the acid cleaning process takes a long time. Further, if it exceeds 78 wt%, the mixture after kneading (hereinafter also referred to as kneaded product) becomes too hard and extrusion molding becomes difficult.

  The average particle diameter of SiC is preferably 100 μm or less in order to cope with extrusion molding. The main factor of metal contamination is often wear during the extrusion process. This is because SiC is a very hard substance. From the viewpoint of reducing the wear, the average particle size of SiC is more preferably 10 μm or less. Most preferably, they are 1 micrometer or more and 5 micrometers or less. When the thickness is 5 μm or less, Si filling between the SiC particles forms a fine network, and the product can have high strength. On the other hand, if it is finer than 1 μm, there is a possibility that Si at the time of cooling expands and cracks occur in the metal Si impregnation step. The average particle size was measured with a laser diffraction / scattering particle size distribution analyzer (LA-950V2) manufactured by Horiba, Ltd.

  The water-soluble resin preferably includes both a resin that functions as an organic binder at the time of kneading and a resin that functions as a surface treatment agent for SiC particles when mixed with the SiC powder. For example, it is preferable to contain both methylcellulose and polyalkylene glycol. Methylcellulose functions as an organic binder during kneading, and polyalkylene glycol functions as a surface treatment agent when mixed with SiC particles. Polyalkylene glycol is generally a water-soluble resin. As described above, the water-soluble resin prevents deformation of the molded body in a wide temperature range including during the drying process in consideration of imparting plasticity during the molding process and maintaining shape retention in each process. The material and the amount of addition are adjusted so that it can function as “paste”. This will be described below.

  As the water-soluble resin that functions as an organic binder, for example, methyl cellulose, ethyl cellulose, carboxymethyl cellulose salt and the like, and a resin obtained by mixing them with a water-soluble phenol resin are suitable. The ratio of the water-soluble resin that functions as an organic binder to the total amount of the kneaded material is preferably 3.5 to 7.5 wt%. Furthermore, 4-7 wt% is more preferable. Hereinafter, the case of methylcellulose will be described as an example. Methylcellulose generally has thermoreversible gelling properties. A type that increases in viscosity with gelation is particularly preferable. The gelation temperature also depends on the aqueous concentration of methylcellulose. For example, in the case of SM-8000 (trade name Metroze, manufactured by Shin-Etsu Chemical Co., Ltd.), by adding water to methylcellulose to obtain an aqueous solution of 15 to 25 wt% (preferably 17 to 22 wt%), the gelation temperature is increased to 50 ° C or higher. And can be handled easily. In this case, the ratio of water to the total amount of the kneaded material is preferably 10 to 40 wt%. Thereby, the effect of the strength improvement of a molded object and a deformation | transformation prevention in a drying process can be acquired. In the case of water-soluble resins that function as other organic binders, the concentration of the aqueous solution may be adjusted while taking into consideration the viscosity characteristics and the gelation temperature. Further, a plurality of water-soluble resins may be included as the organic binder.

  Examples of the water-soluble resin that functions as a surface treatment agent for SiC include polyalkylene glycols such as polyethylene glycol and polypropylene glycol. The SiC powder is first mixed with polyalkylene glycol to form a powder in which the surface of the SiC particles is coated with polyalkylene glycol, and then mixed with the water-soluble resin that functions as the organic binder. By pre-coating the surface of the SiC particles, the SiC particle spacing is made uniform, and the SiC powder surface is made hydrophilic, thereby improving the dispersibility in the organic binder. The addition amount, molecular weight, etc. are determined in consideration of this effect and working temperature.

  The amount of the water-soluble resin that functions as a surface treatment agent for SiC is preferably 0.67 to 1.5 in terms of mass ratio with respect to the water-soluble resin that functions as an organic binder. This is because the flexibility is insufficient when the mass ratio is less than 0.67, and the molding itself is difficult when the mass ratio is greater than 1.5. Furthermore, it is most preferable to add at a mass ratio of 0.9 to 1.1 because a highly accurate molded body with suppressed deformation can be obtained.

  Hereinafter, the case of polyethylene glycol will be described as an example. Polyethylene glycol is a liquid at room temperature and dissolves in water to form an aqueous solution. The input amount of polyethylene glycol is preferably 0.67 to 1.5 in terms of mass ratio with respect to methylcellulose functioning as an organic binder. By setting the mass ratio, in the drying step after molding, the polyethylene glycol aqueous solution covers the molded body in place of methylcellulose that has gelled at 50 ° C. or higher and lost water solubility, imparts flexibility, and is being dried. It is considered that there is an effect of suppressing cracking and deformation. When the mass ratio is smaller than 0.67, the flexibility is insufficient, and when the mass ratio exceeds 1.5, water becomes in contact with each other and the aqueous methylcellulose solution becomes insufficient. Furthermore, it is most preferable to add at a mass ratio of 0.9 to 1.1 because a highly accurate molded body with suppressed deformation can be obtained. In the case of polyalkylene glycol that functions as a surface treating agent for other SiC particles, the composition may be determined in consideration of the working temperature and dispersibility in an organic binder.

  In order to obtain a kneaded product that can be molded at a kneading temperature of 5 to 20 ° C., the molecular weight of polyethylene glycol is preferably 205 to 595. Furthermore, the molecular weight of polyethylene glycol is more preferably 250 to 550. When polyethylene glycol having a molecular weight of 200 or less and methylcellulose are kneaded at a temperature of 5 to 20 ° C. in the above-mentioned mass ratio, moisture is brought into contact with methylcellulose and polyethylene glycol, which can be stably obtained as a kneaded product before the molding step. Is difficult. In addition, when polyethylene glycol having a molecular weight of 600 or more and methylcellulose are kneaded at a mass ratio of 5 to 20 ° C., polyethylene glycol is difficult to express water solubility and is difficult to disperse uniformly. It becomes extremely difficult to mold this. Therefore, by setting the molecular weight of polyethylene glycol to 250 to 550, even when kneaded at a temperature of 5 to 20 ° C., a water-soluble and uniformly dispersed kneaded product can be produced, and the molding temperature is set to 5 to 20 ° C. To obtain a predetermined extruded product.

  As other materials, a lubricant may be included from the viewpoint of reducing wear in an extruder. Although the lubricant may not be water-soluble, it is preferable that at least the dispersibility in water is good.

  The above materials are kneaded well with a kneader.

<Molding process>
A predetermined extrusion die is attached to the extrusion molding machine, and the kneaded material is put into the extrusion molding to perform extrusion molding to obtain a molded body having a desired size and shape. The molding temperature is, for example, 5 to 20 ° C.

<Drying process>
The molded body is wrapped with resin wrap so as not to be exposed, placed in a drying oven at 50 ° C. for 3 hours, for example, and then the wrap is removed and dried at the same temperature. The reason why the wrap is applied first is to obtain a homogeneous structure by preventing the drying from the surface while making the entire molded body at or above the gelation temperature of methylcellulose, thereby eliminating defects such as cracking and deformation. As described above, the drying condition may be a method in which the entire molded body is dried while maintaining a certain degree of humidity as much as possible. From this point of view, there is also a method in which the high humidity and low temperature are initially set, and the low humidity and high temperature are increased with time.

<Degreasing process>
The molded body after drying is heat-treated at a temperature of 350 to 450 ° C. in an inert gas atmosphere. As will be described later, it has been found that the degreasing conditions affect the purity after degreasing and the strength of the molded body after the degreasing step (hereinafter also referred to as degreased body).

  First, as a precondition for effective acid cleaning, degreasing is preferably performed before the acid cleaning step. In this way, in the stage after the drying process, the organic matter surrounding the periphery of the inorganic substance such as Fe, which is an impurity, is first removed, and the subsequent cleaning with acid works effectively. In this way, the inorganic substance, mainly the Fe concentration, can be lowered.

  An inert gas is preferred for the degreasing atmosphere. Examples of the inert gas include nitrogen and argon. Most simply, degreasing in an air atmosphere is considered preferable in terms of degreasing equipment. However, in the case of atmospheric degreasing, the strength of the degreased body is low, and when immersed in an acid, the bonding force between the particles is lost due to the dissolution reaction, and there is a possibility that it will collapse. The oxygen concentration is preferably 5% or less, and more preferably 2% or less. Moreover, when degreasing is performed in a vacuum, the strength of the molded body is improved as compared with that in the air. However, in the next acid washing step, when the sample is moved in the liquid or pulled out of the water, the sample is subjected to force and may be damaged. Thus, in degreasing in vacuum, acid cleaning is possible if handled carefully, but it is difficult to produce industrially.

  According to the knowledge of the inventors, it is important that the bending strength is 1 MPa or more after the completion of the next acid cleaning step, and degreasing in vacuum does not satisfy this condition. Here, the bending strength is based on a three-point bending test using a universal testing apparatus AGS-J manufactured by Shimadzu Corporation.

  On the other hand, when degreasing in an inert gas, particularly in nitrogen, the strength of the degreased body can be increased to 1 MPa or more. Through analysis of the washed product, it was found that carbon remains in the defatted body due to degreasing in nitrogen, and that this exerts the role of a binder, thereby developing strength. The same effect can be obtained even in argon gas. The carbon content after degreasing is preferably at least 1 wt%. As described above, the degreasing atmosphere is preferably an inert gas, most preferably nitrogen that is inexpensive and easily available.

As temperature conditions for degreasing, 350 to 450 ° C. is preferable. If the temperature is higher than 450 ° C., the metal element, which is an impurity attached in the molding process, passes through the SiO ₂ film on the surface of the SiC and diffuses into the SiC particles. It becomes difficult to do. The Fe concentration in the fired body is preferably 5 ppm or less. For that purpose, it is further preferable that the Fe concentration of the molded body (hereinafter also referred to as a cleaning body) after the immediately preceding acid cleaning step is 20 ppm or less. Degreasing at a temperature higher than 450 ° C. is not preferable for a semiconductor manufacturing process because the Fe concentration in the molded body does not sufficiently decrease even after an acid cleaning step.

  When the heat treatment temperature is lowered, it becomes difficult for the metal element to diffuse and easy to clean, but at a temperature lower than 350 ° C., the strength of the degreased body is insufficient and the acid cleaning process collapses. In consideration of the actual furnace temperature distribution, 400 to 450 ° C. is more preferable for reliable degreasing.

  The heat treatment time can be adjusted as appropriate, and is, for example, about 2 to 5 hours.

<Acid cleaning process>
Wash the defatted body with acid. Metal impurities are mixed into the degreased body due to wear of the metal parts of the kneader and molding machine. The elements to be mixed vary depending on the type of metal used in the kneader and molding machine, but mainly Fe, Ni, Cr and the like. In order to remove these metals, the degreased body is preferably immersed in a mixed acid (hereinafter referred to as mixed acid) prepared at a concentration of hydrochloric acid: nitric acid: water = 1: 1: 2. The temperature of the mixed acid is preferably 50 to 100 ° C. This is because the acid cleaning effect is more effectively exhibited. In addition to the mixed acid, normal temperature hydrofluoric acid (HNO ₃ : HF: H ₂ O = 1: 1: 10) also provides the same effect. Further, when the metal to be removed is limited to Fe, it can be cleaned only with hydrochloric acid at 50 to 100 ° C. In any case, the immersion time may be adjusted depending on the contamination state of the molded body, the shape of the molded body, and the like.

<After firing step>
The molded product after acid cleaning, that is, the cleaned product is dried, placed in an atmosphere firing furnace, and fired in vacuum to obtain a fired product.

  Then, it puts into another atmospheric furnace, Si metal of high purity is made to adjoin with a calcination object, Si impregnation processing can be performed, and Si impregnation SiC can be obtained. By further machining this and passing through a CVD process, it can be set as the extremely high purity SiC processing jig suitable for a semiconductor manufacturing process.

<Example 1>
First, SiC particles having an average particle size of 2.3 μm corresponding to 68 wt% of the total amount of the kneaded material by weight ratio and polyethylene glycol (molecular weight 400, manufactured by NOF Corporation) corresponding to 5.2 wt% of the total amount of the kneaded material. The mixture was dispersed and stirred while being irradiated with ultrasonic waves in an ethanol solution. Subsequently, ethanol was evaporated by an evaporator to obtain SiC particles coated with polyethylene glycol. Subsequently, methyl cellulose equivalent to 5.2 wt% of the total amount of the kneaded material in the SiC particles (mass ratio of polyethylene glycol to methyl cellulose is 1.0) (model number SM-8000, trade name Metrolose, manufactured by Shin-Etsu Chemical Co., Ltd.) Of the total amount of the kneaded materials, each of which is obtained by diluting a 20 wt% aqueous solution with water, unilube (trade name 50MB26, manufactured by NOF Corporation) and oleic acid (first grade, manufactured by Junsei Co., Ltd.) as lubricants. The amounts corresponding to 7 wt% and 0.1 wt% were added and kneaded well with a kneader controlled to a temperature of 10 ° C. until uniform. An analytical sample 5 g was collected from the raw material SiC (sample 1).

  Next, a predetermined extrusion die was attached to an extrusion molding machine whose temperature was controlled at 10 ° C., and the kneaded material was charged to perform extrusion molding. As a result, a molded body having a thickness of 5 mm (millimeters) × width of 50 mm × 300 mm was obtained.

  The molded body was immediately wrapped and placed in a drying oven at 50 ° C. for 3 hours, and then the wrap was removed and dried at the same temperature for 165 hours.

  Subsequently, degreasing was performed by heat treatment at 425 ° C. for 3 hours while flowing nitrogen (flow rate 5 L / min) into the furnace in order to remove organic substances in the molded body. From this degreased body, 5 g was collected as a sample for analysis (sample 2). Subsequently, the resulting defatted body was immersed in the mixed acid for 6 hours by heating the mixed acid to a temperature of 80 ° C. Then, after taking out a sample, the operation | work immersed in pure water for 30 minutes was repeated 3 times. From this washed body, 5 g was collected as a sample for analysis (sample 3).

  The washed body was dried, placed in an atmosphere firing furnace, and fired in a vacuum at 1700 ° C. to obtain a fired body. Again, about 5 g of a sample for analysis was collected (Sample 4).

  Then, it put into another atmospheric furnace, Si impregnation process was performed by making high purity Si metal adjoin to a calcination object, and Si impregnation SiC object was obtained.

  Sample 1, Sample 2, Sample 3, and Sample 4 obtained by this operation were analyzed for iron (Fe) as an impurity using a fluorescent X-ray apparatus in which a calibration curve had been prepared in advance. The results are shown in Table 1. As a result, the Fe concentration after washing was 20 ppm or less, and the Fe concentration was 5 ppm or less, which is important as the Fe concentration after firing.

  In addition, five test pieces having a width of 11 to 12 mm, a thickness of 8 to 9 mm, and a length of 50 mm were cut out from the cleaned body, and a head speed of 0.1 mm / min and a span of 40 mm were used using a universal testing apparatus AGS-J manufactured by Shimadzu Corporation. A three-point bending test was performed under the conditions. As a result, the bending strength showed an average of 1.9 MPa. This satisfies the bending strength of 1 MPa or more required after washing.

<Example 2>
A washed body was obtained in the same manner as in Example 1 except that degreasing was performed at 450 ° C. The bending strength of the cleaned product was 2.0 MPa, and the Fe concentration was 4 ppm.

<Example 3>
A washed body was obtained in the same manner as in Example 1 except that degreasing was performed at 400 ° C. The bending strength of the washed product was 1.6 MPa.

<Example 4>
A washed product was obtained in the same manner as in Example 1 except that the degreasing was performed at 375 ° C. The bending strength of the washed product was 1.6 MPa.

<Example 5>
A washed product was obtained in the same manner as in Example 1 except that degreasing was performed at 350 ° C. The bending strength of the cleaned product was 1.6 MPa, and the Fe concentration after cleaning was 9 ppm. The washed product was dried, placed in an atmosphere firing furnace, and fired in a vacuum at 1700 ° C. to obtain a fired body. The Fe concentration of the fired body was 2 ppm, and the Fe concentration required as the Fe concentration after firing was 5 ppm or less.

<Example 6>
A cleaning body was obtained in the same manner as in Example 1 except that it was degreased at 425 ° C. and washed with hydrofluoric acid at room temperature. The washed product had a bending strength of 2.0 MPa and an Fe concentration of 10 ppm. The washed product was dried, placed in an atmosphere firing furnace, and fired in a vacuum at 1700 ° C. to obtain a fired body. The Fe concentration of the fired body was 3 ppm, and the Fe concentration required as the Fe concentration after firing was 5 ppm or less.

<Comparative Example 1>
A molded body kneaded, molded and dried in the same manner as in Example 1 was degreased in a nitrogen atmosphere at 325 ° C. and washed with a mixed acid. After being washed with the mixed acid, the molded body was damaged when taken out from the container.

<Comparative example 2>
A washed product was obtained in the same manner as in Example 1 except that degreasing was performed at 500 ° C. The Fe concentration after washing was 40 ppm. The washed product was dried, placed in an atmosphere firing furnace, and fired in a vacuum at 1700 ° C. to obtain a fired body. The Fe concentration of the fired body was 10 ppm, and did not become 5 ppm or less, which is necessary as the Fe concentration after firing.

<Comparative Example 3>
A molded body kneaded, molded and dried in the same manner as in Example 1 was degreased in the atmosphere at 450 ° C. and washed with a mixed acid. The degreased body was cracked in the acid solution.

<Comparative example 4>
A washed body was obtained in the same manner as in Example 1 except that the degreasing was performed in a vacuum of 450 ° C. The Fe concentration after washing was 10 ppm. The bending strength of the cleaned body was 0.5 MPa, which was less than the required bending strength of 1 MPa after cleaning.

  The above results are summarized in Table 2. In addition, shape retention property is a property resulting from strength, and it is marked as “X” when it is damaged during the manufacturing process (excluding accidents and mistakes in handling).

  The manufacturing process of the present application, particularly the acid cleaning process, is suitable for manufacturing a SiC processing jig used in a heat treatment process of semiconductor manufacturing by an extrusion method at a low cost and with a low environmental load.

Claims (8)

A kneading step of kneading SiC powder, a water-soluble resin, and water to obtain a kneaded product;
A molding step of obtaining a molded body by extruding the kneaded product;
A drying step of drying the molded body;
A degreasing step of heat-treating the molded body after the drying step in an inert gas atmosphere at a temperature of 350 to 450 ° C;
The manufacturing method of the SiC member for semiconductor manufacturing processes which has an acid cleaning process which wash | cleans the said molded object after a degreasing process with an acid.   The production method according to claim 1, wherein the acid is a mixed acid of hydrochloric acid, nitric acid and water, hydrofluoric acid, or hydrochloric acid. A kneading step of obtaining a kneaded product by kneading SiC powder, a water-soluble resin, and water at a temperature of 5 to 20 ° C .;
A molding step of extruding the kneaded material at a temperature of 5 to 20 ° C. to obtain a molded body;
A drying step of drying the molded body at a temperature of 50 ° C. or higher;
A degreasing step of heat-treating the molded body after the drying step in an inert gas atmosphere at a temperature of 350 to 450 ° C;
The manufacturing method of the SiC member for semiconductor manufacturing processes which has an acid cleaning process which wash | cleans the said molded object after a degreasing process with an acid.   The manufacturing method according to any one of claims 1 to 3, wherein the acid is a mixed acid of hydrochloric acid, nitric acid and water at 50 to 100 ° C, hydrochloric acid at 50 to 100 ° C, or hydrofluoric acid at room temperature.   The manufacturing method of any one of Claims 1-4 whose inert gas is nitrogen.   The average particle diameter of SiC powder is 1-10 micrometers, The ratio of SiC powder is 66-78 wt% with respect to the total amount of a kneading | mixing material, The manufacture of any one of Claims 1-5 Method.   The manufacturing method of any one of Claims 1-6 containing methylcellulose and polyethyleneglycol whose molecular weight is 250-550 as water-soluble resin.   The manufacturing method of any one of Claims 1-7 containing methylcellulose and polyethyleneglycol as water-soluble resin, and mass ratio with respect to methylcellulose of polyethyleneglycol is 0.67-1.5.

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