JP2019055897A - Production method of silicon carbide member - Google Patents

Abstract

To provide a production method of silicon carbide member capable of jointing a silicon carbide sintered body and a silicon carbide body formed by a CVD method without interposing a joint material.SOLUTION: The method includes: a first polish step S1 of polishing a joint area 11 of a first silicon carbide member 10 composed of a silicon carbide sintered body; a second polish step S2 of polishing a second joint area 21 of a second silicon carbide member 20 formed by a chemical vapor growth method; and a junction step S3 of jointing the first silicon carbide member 10 and the second silicon carbide member 20 with heating, while pressurizing contacted jointing areas 11, 21 by pressing the first silicon carbide member 10 and the second silicon carbide member 20 toward each joint area 11, 21 with the joint areas 11, 21 directly contacted to each other under inert atmosphere.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for manufacturing a silicon carbide member.

  Silicon carbide (SiC) sintered bodies are widely used for fixing members and the like in semiconductor manufacturing apparatuses, liquid crystal manufacturing apparatuses, etc. in view of their properties of high strength, high rigidity, and high wear resistance. However, since the silicon carbide sintered body is obtained by sintering silicon carbide powder, voids are unavoidably present on the surface or inside of the structure, and the bonding strength between the particles is locally inferior, There was a risk of dust generation from particles from the periphery.

  Therefore, it has been studied to use a silicon carbide body formed by a chemical vapor deposition (CVD) method, which has higher strength and higher rigidity than a silicon carbide sintered body. However, this silicon carbide body is inferior in productivity and expensive as compared with the case of producing a silicon carbide sintered body. Therefore, it has been proposed to suppress low productivity and high cost by using a member obtained by bonding a silicon carbide sintered body formed by a CVD method to a silicon carbide sintered body.

  For example, Patent Document 1 discloses that a base material portion made of a silicon carbide sintered body and a molding surface portion made of a silicon carbide body formed by a CVD method are bonded via a bonding material.

Japanese Patent No. 4917844

  However, a structural member used in a semiconductor manufacturing apparatus or the like is often exposed to a corrosive environment such as a plasma etching process or a high temperature environment such as a film forming process, and a bonding material is used as in Patent Document 1 described above. In the case of joining together, the joining material is inferior in plasma corrosion resistance and heat resistance as compared with a silicon carbide sintered body or the like, so that the structural member has a problem of inferior in plasma corrosion resistance and heat resistance as a whole.

  This invention is made in view of the said conventional problem, and manufacture of the silicon carbide member which can join the silicon carbide sintered compact and the silicon carbide body formed by CVD method, without passing through a joining material. It aims to provide a method.

  The method for producing a silicon carbide member of the present invention includes a first polishing step for polishing a bonding surface of a first silicon carbide member made of a silicon carbide sintered body, and a second carbonization formed by a chemical vapor deposition method. A second polishing step for polishing the bonding surface of the silicon member; and a bonding surface of the polished first silicon carbide member and a polished bonding surface of the second silicon carbide member in an inert atmosphere. Directly abutting and heating the first silicon carbide member and the second silicon carbide member while pressing the abutting joint surfaces by pressing the first silicon carbide member and the second silicon carbide member against the respective joint surfaces. A bonding step of bonding the first silicon carbide member and the second silicon carbide member, and the first silicon carbide member and the second silicon carbide member in the pressed direction. Dimensional reduction rate is 0.125 to 1% .

  According to the method for manufacturing a silicon carbide member of the present invention, as can be seen from the examples described later, the first silicon carbide member made of a silicon carbide sintered body and the chemical vapor deposition method are used without using a bonding material. It becomes possible to directly join the formed second silicon carbide member. If the dimensional reduction rate of the first and second silicon carbide members is less than 0.125%, the first silicon carbide member and the second silicon carbide member are not sufficiently joined. On the other hand, when the dimensional reduction rate of the first and second silicon carbide members exceeds 1%, the deformation of the first and second silicon carbide members becomes excessively large and the desired shape cannot be maintained, and many additional processes are required. Is required. The smaller the dimensional reduction rate of the first and second silicon carbide members, the easier the design of the shape of the silicon carbide member after joining.

  In the manufacturing method of the silicon carbide member of this invention, it is preferable to heat at the temperature of 2000-2200 degreeC at the said joining process.

  If the bonding temperature is less than 2000 ° C., the first silicon carbide member and the second silicon carbide member are not sufficiently bonded, and if the bonding temperature exceeds 2200 ° C., the first and second carbonization members. This is because the deformation of the silicon member becomes excessively large, the desired shape cannot be maintained, and many additional processes are required, leading to a reduction in productivity and an increase in cost.

  Moreover, in the manufacturing method of the silicon carbide member of this invention, it is preferable to apply the pressure of 0.1-10 Mpa to the said joined surface which contact | abutted at the said joining process.

  This is because if the bonding pressure is less than 0.1 MPa, the first silicon carbide member and the second silicon carbide member are not sufficiently bonded, and if the bonding pressure exceeds 10 MPa, the first and second carbonization members. This is because the deformation of the silicon member becomes excessively large, the desired shape cannot be maintained, and additional work is required.

  In the method for manufacturing a silicon carbide member of the present invention, in the first polishing step, the bonding surface of the first silicon carbide member is polished to a surface roughness Ra of 0.005 to 0.4 μm, In the polishing step 2, it is preferable to polish the bonding surface of the second silicon carbide member until the surface roughness becomes 0.001 to 0.4 μm.

  This is because if the surface roughness Ra of the bonding surface exceeds 0.4 μm, contact between the bonding surfaces is insufficient in the bonding step, bonding becomes insufficient, and peeling may occur. On the other hand, since the surface roughness of the bonding surface is affected by pores contained in the first and second silicon carbide members, the surface roughness Ra of the bonding surface of the first silicon carbide member is less than 0.005 μm, or It is difficult to make the surface roughness Ra of the joint surface of the second silicon carbide member less than 0.001 μm.

The schematic sectional drawing of the manufacturing method of the silicon carbide member which concerns on embodiment of this invention is shown, FIG. 1A shows the 1st and 2nd grinding | polishing process, FIG. 1B shows a joining process, FIG. 1C shows the state after a joining process, respectively. The flowchart of the manufacturing method of the silicon carbide member which concerns on embodiment of this invention. The graph which shows the dimension reduction rate of a 1st silicon carbide member. The photograph which observed the joining interface of the silicon carbide member with the microscope microscope is shown, and Drawing 4A shows Example 1 and Drawing 4B shows Example 2, respectively.

  A method for manufacturing a silicon carbide (SiC) member according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2. The manufacturing method includes first and second polishing steps S1, S2 and a joining step S3.

  First, as shown to FIG. 1A, 1st grinding | polishing process S1 which grind | polishes the joint surface 11 of the 1st silicon carbide member 10 which consists of a silicon carbide sintered compact is performed. The silicon carbide sintered body uses granules granulated from a raw material obtained by adding a binder, a dispersant and the like to silicon carbide powder, a molding method such as atmospheric pressure molding, press molding, CIP molding, and atmospheric pressure sintering, What is necessary is just to produce by sintering methods, such as pressure sintering and reaction sintering. Boron carbide, graphite or the like may be added to the raw material powder as a sintering aid.

  In the first polishing step S1, it is preferable to polish the bonding surface 11 of the first silicon carbide member 10 until the surface roughness Ra becomes 0.005 to 0.4 μm.

  Moreover, the 2nd grinding | polishing process S2 which grind | polishes the joining surface 21 of the 2nd silicon carbide member 20 formed by the chemical vapor deposition (Chemical Vapor Deposition: CVD) method is performed. The second silicon carbide member 20 may be formed by a conventionally known CVD method such as a thermal CVD method, a plasma CVD method, a super growth method, or an alcohol CVD method.

  In the second polishing step S2, it is preferable to polish the bonding surface 21 of the second silicon carbide member 20 until the surface roughness becomes 0.001 to 0.4 μm.

  The polishing in the first and second polishing steps S1 and S2 is preferably performed using a grindstone after being ground by a surface grinder, a machining center, or the like. Further, after polishing with a grindstone, it is also preferable to polish with a lapping machine, a polish machine or the like. If the surface roughness Ra of the bonding surfaces 11 and 21 exceeds 0.4 μm, in the bonding step S3, contact between the bonding surfaces 11 and 21 may be insufficient, bonding may be insufficient, and peeling may occur. is there.

  The flatness of the joining surfaces 11 and 12 is preferably 10 μm or less, and more preferably 5 μm or less. If the flatness of the bonding surfaces 11 and 12 exceeds 10 μm, even if the first silicon carbide member 10 and the second silicon carbide member 20 are pressed toward the bonding surfaces 11 and 21 respectively in a bonding step S3 described later. This is because insufficient contact between the bonding surfaces 11 and 21 occurs, bonding becomes insufficient, and peeling may occur.

Then, as shown in FIG. 1B, the bonding surface 11 of the polished first silicon carbide member 10 and the polished second silicon carbide member 20 in an inert atmosphere such as N ₂ , Ar, or a vacuum atmosphere. The joining surface 11 is brought into contact by directly contacting the joining surface 21 and pressing the first silicon carbide member 10 and the second silicon carbide member 20 toward the joining surfaces 11 and 21. The first silicon carbide member 10 and the second silicon carbide member 20 are joined by heating while applying pressure to the first and second silicon carbide members 30, and a joining step S3 for obtaining the silicon carbide member 30 is performed. Thereby, silicon carbide member 30 that is not bonded via the bonding material can be obtained.

  In joining process S3, it is preferable to heat at the temperature of 2000-2200 degreeC. If joining temperature is less than 2000 degreeC, the 1st silicon carbide member 10 and the 2nd silicon carbide member 20 will not fully join. On the other hand, if the bonding temperature exceeds 2200 ° C., the deformation of the first and second silicon carbide members 10 and 20 becomes excessively large and the desired shape cannot be maintained, and additional work is required.

  In the joining step S3, it is preferable to apply a pressure of 0.1 to 10 MPa to the abutting joining surfaces 11 and 21. If the bonding pressure is less than 0.1 MPa, first silicon carbide member 10 and second silicon carbide member 20 are not sufficiently bonded. On the other hand, if the bonding pressure exceeds 10 MPa, the deformation of the first and second silicon carbide members 10 and 20 becomes excessively large, the desired shape cannot be maintained, and additional work is required.

  In joining process S3, it is preferable to press so that the dimensional reduction rate T of the 1st silicon carbide member 10 and the 2nd silicon carbide member 20 in the pressed direction may be 0.125 to 1%. Here, the dimensional reduction rate T of the first silicon carbide member 10 and the second silicon carbide member 20 is the first in the pressing direction (in the thickness direction when pressing in the thickness direction) L1. The sum of the length of the silicon carbide member 10 and the length of the second silicon carbide member 20, and L2 is “the pressing direction after the bonding step S3 (in the thickness direction when pressing in the thickness direction) 30”. Is expressed by the formula (L1-L2) / L1 × 100.

  If dimensional reduction rate T of first silicon carbide member 10 and second silicon carbide member 20 is less than 0.125%, first silicon carbide member 10 and second silicon carbide member 20 are sufficiently bonded. do not do. On the other hand, when the dimensional reduction rate T of the first silicon carbide member 10 and the second silicon carbide member 20 exceeds 1%, the deformation of the first and second silicon carbide members 10 and 20 becomes excessively large, and the desired The shape cannot be maintained, and a lot of additional work is required.

  Note that the dimensional reduction rate T of the first silicon carbide member 10 and the second silicon carbide member 20 depends on the bonding temperature, the bonding pressure, the bonding time, and the like. The dimensional reduction rate T of the first silicon carbide member 10 and the second silicon carbide member 20 increases as the bonding temperature increases, the bonding pressure increases, and the bonding time increases.

  FIG. 3 is a graph showing the dimensional reduction rate T of the first silicon carbide member 10 and the second silicon carbide member 20 when the bonding temperature and the bonding pressure are changed and the other bonding conditions are constant. As can be seen from this graph, the first silicon carbide member 10 made of the silicon carbide sintered body and the second silicon carbide member 20 formed by the CVD method are compared with the case where the silicon carbide sintered bodies are joined together. It can be seen that the dimensional reduction rate T of the first silicon carbide member 10 and the second silicon carbide member 20 is reduced when bonding is performed.

  In addition, this invention is not limited to embodiment mentioned above. For example, a plurality of bonding surfaces 11 of the first ceramic member 10, for example, the front and back surfaces may be the bonding surfaces 11, and the second ceramic member 20 may be bonded to each bonding surface 11.

  Hereinafter, the present invention will be described in detail with specific examples of the present invention.

(Example)
First, first silicon carbide member 10 was produced by a known process for forming a silicon carbide sintered body. Specifically, silicon carbide powder having an average particle size of 1 μm or less, B ₄ C as a sintering aid is 0.1 to 0.5 mass%, C (carbon black) is 2 to 4 mass%, and molding aid is used. A material powder added with a binder such as PVA was used as a raw material powder. As the silicon carbide powder, α-type (hexagonal) type was used.

  Next, this raw material powder was granulated with a spray dryer or the like and then subjected to normal pressure molding. And the 1st silicon carbide member 10 was obtained from the silicon carbide sintered compact by baking at 2000 degreeC-2200 degreeC in argon atmosphere. The obtained first silicon carbide member 10 was α-type (hexagonal).

  First silicon carbide member 10 was formed into a disk shape having a diameter of 100 mm and a thickness of 3.5 mm by grinding. Then, in the first polishing step S1, one surface (the lower surface in FIG. 1A) was polished using a # 800 grindstone until the surface roughness Ra became 0.4 μm. Then, it further grind | polished until the surface roughness Ra became 0.01 micrometer using the loose abrasive grain of a diamond with a particle diameter of 1 micrometer. In the center of the first silicon carbide member 10, a through hole having a diameter of 5 mm penetrating between the upper surface and the lower surface of FIG. 1A was formed. This through hole is a test port used for airtightness evaluation described later.

Second silicon carbide member 20 was manufactured by a known process for forming a silicon carbide body by a CVD method. Specifically, second silicon carbide member 20 was formed by a thermal CVD method in which a silicon carbide body was formed on a high purity isotropic graphite material by heating film formation. As a source gas, a mixed gas of trichloromethylsilane (CH ₃ SiCl ₃ : MTS) and hydrogen gas was used. The second silicon carbide member 20 was obtained by removing the graphite material after film formation. The obtained second silicon carbide member 20 was β-type (cubic).

  Second silicon carbide member 20 was formed into a disk shape having a diameter of 100 mm and a thickness of 4.5 mm by grinding. Then, in the second polishing step S2, one surface (the upper surface in FIG. 1A) was polished using a # 800 grindstone until the surface roughness Ra became 0.4 μm. Then, it further grind | polished until the surface roughness Ra became 0.005 micrometer using the loose abrasive grain of a diamond with a particle diameter of 1 micrometer.

  Next, in the joining step S3, in a state where the joining surfaces 11 and 21 of the first and second silicon carbide members 10 and 20 are in contact with each other, they are put in a firing furnace and reach the maximum temperature in an Ar atmosphere. Then, the silicon carbide member 30 was obtained by firing for 6 hours.

  The firing temperature and firing pressure in the joining step S3, and the thickness change amount (pressing direction change amount) L1-L2 and the thickness change rate (dimension reduction rate) T of the first silicon carbide member 10 and the second silicon carbide member 20 are as follows. Table 1 shows.

  When silicon carbide member 30 was cut and the interface between first silicon carbide member 10 and second silicon carbide member 20 was originally observed with a microscope, α-type first silicon carbide member 10 and It was observed that a local gap due to insufficient pressing was not formed at the bonding interface with the β-type second silicon carbide member 20 originally, and the bonding was satisfactorily performed.

  FIG. 4A shows a photograph of the interface of Example 1 and FIG. 4B shows a photograph of the interface of Example 2 observed with a microscope.

In addition, Table 1 shows the leakage amount as a result of evaluating the airtightness of the bonding interface between the first and second silicon carbide members 10 and 20 using the He leak detector. As a method for evaluating the airtightness, a He leak detector pipe was arranged at the test port of the silicon carbide member 30 and the amount of leak when helium was sprayed on the side surface of the silicon carbide member 30 was measured.
In Examples 1 to 6 in which the rate of change in thickness was 0.125% or more, the leak amount was suppressed to 10 ⁻⁹ Pa · m ³ / s or less, so that sufficient airtightness was obtained and good bonding was achieved. It has been confirmed that. In Examples 1 to 4 and 6 in which bonding was performed at 2000 ° C. or higher, the leak amount was 10 ⁻¹⁰ Pa · m ³ / s or less, and it was confirmed that better airtightness was obtained.

(Comparative example)
Silicon carbide member 30 of comparative example 1 was produced by the same method as in example 1 except that the bonding temperature was changed. In Comparative Example 1, since the rate of change in thickness was too small, the amount of leak was large, and the first silicon carbide member 10 and the second silicon carbide member 20 could not be joined well.

  DESCRIPTION OF SYMBOLS 10 ... 1st silicon carbide member, 11 ... Joining surface, 20 ... 2nd silicon carbide member, 21 ... Joining surface, 30 ... Silicon carbide member, S1 ... 1st grinding | polishing process, S2 ... 2nd grinding | polishing process, S3: Joining step.

Claims (4)

A first polishing step of polishing a bonding surface of a first silicon carbide member made of a silicon carbide sintered body;
A second polishing step of polishing the bonding surface of the second silicon carbide member formed by chemical vapor deposition;
In an inert atmosphere, the polished bonding surface of the first silicon carbide member and the polished bonding surface of the second silicon carbide member are brought into direct contact with each other, and the first silicon carbide member and The first silicon carbide member and the second silicon carbide member are heated by pressing the second silicon carbide member against each of the joint surfaces while applying pressure to the contact surfaces that are in contact with each other. A bonding step of bonding the silicon carbide member of
The method of manufacturing a silicon carbide member, wherein a dimensional reduction rate of the first silicon carbide member and the second silicon carbide member in the pressed direction is 0.125 to 1%.   In the said joining process, it heats at the temperature of 2000-2200 degreeC, The manufacturing method of the silicon carbide member of Claim 1 characterized by the above-mentioned.   3. The method for manufacturing a silicon carbide member according to claim 1, wherein in the joining step, a pressure of 0.1 to 10 MPa is applied to the abutting joining surfaces. In the first polishing step, the bonding surface of the first silicon carbide member is polished until the surface roughness Ra becomes 0.005 to 0.4 μm,
4. The method according to claim 1, wherein, in the second polishing step, the bonding surface of the second silicon carbide member is polished until the surface roughness Ra becomes 0.001 to 0.4 μm. 5. The manufacturing method of the silicon carbide member of description.