JP2011162422A - Surface-treated ceramic member and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface-treated ceramic member having less particles scattered even in a use environment of an elevated temperature of 250°C or higher. <P>SOLUTION: The surface-treated ceramic member has a film-forming surface on at least a part of a ceramic sintered compact substrate of a porosity of 1% or less, wherein the concave part on the surface of the ceramic sintered compact substrate is selectively coated with a film of an oxide. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a surface-treated ceramic member and a method for manufacturing the same. More specifically, the present invention relates to a surface-treated ceramic member suitable for use in a member subjected to heat treatment, or a member exposed to a processing gas atmosphere, a plasma atmosphere, or a vacuum atmosphere during heat treatment, and a method for manufacturing the same. The present invention further relates to a vacuum processing apparatus using a surface-treated ceramic member.

Ceramics having excellent corrosion resistance are used for members exposed to corrosive gases such as plasma chamber members for semiconductor device manufacturing apparatuses. This is because a material with poor corrosion resistance has a problem that the device life is short, and a reaction product with a corrosive gas adheres to the device as particles, which may cause deterioration of the quality of the device. For such applications, materials having higher corrosion resistance such as AlN and Y ₂ O ₃ are used in addition to general ceramic materials such as alumina.

  However, changing the material alone does not completely prevent the generation of particles. That is, since the ceramic member is a processed product of a brittle material, there are always concave portions (pores, microcracks, processing flaws, etc.) on the surface layer. In some cases, fine particles generated in the surface grinding process or the like enter the recess. It is difficult to completely remove such fine particles in the recess even after a normal cleaning process. In addition, micro cracks may occur during the manufacturing process of the ceramic member. When such fine particles and microcracks are exposed to a high temperature atmosphere, a processing gas atmosphere, a plasma atmosphere, a vacuum atmosphere during heat treatment, or the like, they are scattered as particles.

  Conventionally, several proposals have been made on methods for preventing scattering of particles of ceramic members.

  In Patent Document 1, “a method for cleaning a ceramic product, in which a solvent is applied to the surface to be cleaned of the ceramic product, and then a film made of a material soluble in the solvent is brought into contact with the surface to be cleaned, An invention relating to “a method for cleaning a ceramic product, wherein the surface to be cleaned is cleaned by peeling the film from the surface to be cleaned” is disclosed. In this invention, the contact portion of the film to the surface to be cleaned is melted by the solvent and follows the unevenness of the shape of the surface to be cleaned, so that the particles present on the surface to be cleaned are wrapped in the melted portion of the film. As a result, when the film is peeled off from the surface to be cleaned, particles are fixed on the contact surface side of the film and removed from the surface to be cleaned.

Patent Document 2 discloses that “99.2% by weight or more and 99.99% by weight or less of aluminum oxide and the balance is an oxide of a metal other than aluminum, the average particle diameter is 0.5 μm or more and 15 μm or less, and A sintered body having a density of 3.88 g / cm ³ or more and 3.97 g / cm ³ or less, or a sintered sintered body at a temperature of 1000 ° C. or more and 1550 ° C. or less for 0.1 hour or more and 6 hours or more. An invention relating to an “alumina ceramic sintered body characterized by being heat treated over the following” is disclosed.

  In addition, as a method for improving the corrosion resistance of ceramic materials, an invention for forming a film having high corrosion resistance has been proposed.

  Patent Document 3 states that “a corrosion-resistant composite member used in a halogen-based corrosive gas environment or in a plasma environment of a halogen-based corrosive gas, the base material and at least a halogen-based corrosive gas or a halogen-based corrosive gas on the base material. And a coating formed of a ceramic sol / gel provided at a portion exposed to the plasma of the above, an invention relating to a “corrosion resistant composite member” is disclosed.

  Patent Document 4 states that “a single metal, alloy, cermet, or ceramic is sprayed on the surface of a base material that has been pre-processed for thermal spraying, and then a sealed material is formed in the pores in the thermal spray coating. After applying or impregnating the pore liquid, performing aging or heat treatment and sealing treatment, a solution in which the vitreous forming component is dissolved or suspended is applied by brushing or spraying, and dried at room temperature or at a temperature of 900 ° C. or lower. An invention relating to “a method of forming a composite film having corrosion resistance, characterized by forming a glassy surface film by firing and having a long-term use” is disclosed.

  Patent Document 5 states that “a composite coating material provided on a ceramic member, comprising: a ceramic porous body having open pores; and a resin impregnated in the open pores. The invention relating to “material” is disclosed, and in the examples, only the ceramic porous body formed by the thermal spraying method is described.

  In Patent Document 6, “a ceramic insulating layer obtained by thermal spraying is made of a thermosetting resin at the entrance of pores generated in the ceramic insulating layer by utilizing the difference in shrinkage due to the temperature difference between the gas and the resin. An invention relating to a “sealing treated ceramic insulating layer characterized in that a sealing body is formed” is described.

  In Patent Document 7, “a corrosion-resistant member in which a corrosion-resistant film made of ceramics fired after coating is formed on the surface of a substrate, and the surface of the corrosion-resistant film is magnified by a scanning electron microscope is observed. Further, an invention relating to a corrosion-resistant member characterized in that the area occupation ratio of crystal grains is 70% or more is disclosed. In Patent Document 7, a main surface of a corrosion-resistant member is impregnated with a slurry containing fine particles of 0.01 μm or more and 0.1 μm or less, and then fired at a heat treatment temperature of 500 ° C. or more to form a corrosion-resistant film. Yes.

  Patent Document 8 states that “a ceramic coating member in which a ceramic film having a purity of 98% or more, a film thickness of 0.05 μm or more and 10 μm or less, and an average particle diameter of 50 nm or less is formed on the surface of a substrate. Is disclosed. In Patent Document 8, a coating film formed using a solution or dispersion containing at least one kind of metal alkoxide, organometallic complex, oxide nanoparticle or non-oxide nanoparticle is dried on the surface of a substrate, Thereafter, heat treatment is performed at a temperature of 300 ° C. or higher and 1000 ° C. or lower to form a ceramic film.

  Patent Document 9 states that “an yttrium-based ceramic film having an amorphous structure of 10 nm to 500 nm is formed on a substrate surface, and a crystalline yttrium-based ceramic film is formed thereon. An invention relating to “materials” is disclosed. In Patent Document 9, an yttrium-based MOD coating agent is applied, and then a heat treatment (specifically, a heat treatment at 200 ° C. or higher and 800 ° C. or lower) is performed to form a crystalline yttrium-based ceramic film.

Japanese Patent Application Laid-Open No. 11-21187 JP-A-8-81258 JP 2003-335589 A JP 2001-152307 A Japanese Patent Laid-Open No. 2003-119087 JP 2002-180233 A JP 2009-29686 A JP 2008-120654 A JP 2006-199545 A

  In the invention described in Patent Document 1, a film is formed on the surface of the ceramic and the fine particles that cause particles are removed by peeling the film from the surface to be cleaned. It is difficult to remove fine particles.

  In the invention described in Patent Document 2, microcracks that cause particles are repaired by heat treatment at 1000 to 1550 ° C., but the fine particles that enter the grain boundaries and pores cannot be removed.

  The inventions described in Patent Documents 3 to 6 are all for the purpose of forming a film on thermal sprayed ceramics, and do not solve the problem of particles in the first place. Moreover, since patent documents 3 to 5 form a film on the entire surface of the ceramic surface, the function of the ceramic cannot be exhibited.

  In the case of a method of forming a film by thermal spraying of ceramics or the like and reducing particles, for example, for parts that require periodic cleaning, since the thermal spraying itself peels off from the member by cleaning, one or several times It is necessary to re-spray every cleaning. The spraying cost for each cleaning is a factor that increases the running cost of the apparatus. In order to reduce this cost, an invention of a permanently effective processing method is required.

  The inventions described in Patent Documents 7 to 9 all form a relatively thick film (ceramic film such as yttrium) on a ceramic substrate, and are basically formed on the surface of the substrate. The coating is intended to ensure corrosion resistance. In any case, it is considered that there is a certain effect in terms of improving the corrosion resistance, but the generation of particles has not been sufficiently studied. Therefore, during use in a semiconductor process, there may be a problem that a film formed on the surface of the base material is peeled off or powder is scattered.

  In order to solve the above problems, the present inventors conducted extensive research on a method for permanently preventing the generation of particles while maintaining the excellent corrosion resistance of the ceramic sintered body. Got.

  (A) If the entire surface of the ceramic sintered body is covered with a film, the function inherent to the ceramic sintered body cannot be exhibited, and the function as a corrosion-resistant member depends on the performance of the film. Further, in the case of full-surface coating, there is a problem of durability such as peeling. Therefore, it is desirable to have a configuration that does not cover the entire surface of the ceramic sintered body (the entire surface in contact with the processing atmosphere).

  (B) One of the causes of generation of particles is due to scattering of ceramic fine particles generated during firing or grinding. That is, the ceramic fine particles scattered in the firing furnace and the ceramic fine particles generated during the grinding process adhere to the surface of the ceramic sintered body, but even if various conventionally known cleaning methods such as ultrasonic cleaning are used. It is difficult to completely remove the fine particles that have entered the gaps between the crystal grain boundaries, the micropores, the processing flaws, and the like. Therefore, it is necessary to fix the ceramic fine particles in the minute space instead of removing the ceramic fine particles remaining in the minute space.

  (C) Another cause of the generation of particles is that microscopic pieces generated by microcracks generated in the ceramic member fall off during operation of the apparatus. Therefore, it is necessary that a fixing material for preventing the micro-pieces from dropping off due to micro cracks is present on the surface of the ceramic member.

  (D) Particles due to the causes described in (B) and (C) above are generated in large quantities at a relatively early stage of operation of the apparatus. When a conventional ceramic member is used, the amount of generated particles is gradually reduced by continuing operation, but product processing cannot be performed until the number of particles is reduced to a usable number.

Based on the above findings, the present inventors applied a coating material to a ceramic sintered body in Japanese Patent Application No. 2008-211289, wiped with a waste cloth or the like before it was completely cured, dried, and cured, An invention relating to surface-treated ceramics in which a substrate surface and a film surface are mixed on the treated surface is proposed. In this surface-treated ceramic, particles were hardly generated until the use environment was about 200 ° C., but it was found that the coating material decomposes and particles increase as the use environment becomes high temperature. As a result of intensive studies on this problem, the present inventors have obtained the following knowledge (E).

  (E) The film selectively coated on the recesses on the surface of the ceramic sintered body base material becomes an oxide film when heat treatment is performed at a temperature equal to or higher than the thermal decomposition temperature. The oxide film thus formed does not peel off or scatter even in a use environment of 250 ° C. or higher.

  The present invention has been made on the basis of the above knowledge, and exhibits a function inherent to a ceramic sintered body, and in particular, a ceramic member in which particle scattering does not occur even in a use environment of 250 ° C. or higher and its manufacture It aims to provide a method.

  The gist of the present invention is the surface-treated ceramic member shown in the following (1) to (3) and the method for producing the surface-treated ceramic member shown in the following (4) to (8).

  (1) A ceramic member having a film-forming surface on at least a part of a ceramic sintered body base material having a porosity of 1% or less, wherein a concave portion on the ceramic sintered body base material is selectively covered with an oxide film A surface-treated ceramic member characterized by being made.

  (2) The surface-treated ceramic member according to the above (1), wherein the oxide film is a film that is coated with the metal oxide precursor composition and then converted into an oxide by heat treatment.

  (3) The surface-treated ceramic member according to (1) or (2), which is used in a semiconductor or electronic device manufacturing apparatus.

  (4) A coating material composed of a metal oxide precursor composition is applied to the surface of a ceramic sintered body base material having a porosity of 1% or less, and the coating material is the surface of the ceramic sintered body base material before curing. A method for producing a surface-treated ceramic member, comprising: removing a part of the coating material under conditions such that the coating material remains, curing the coating material, and then oxidizing the coating material.

  (5) The method for producing a surface-treated ceramic member according to (4), wherein part of the coating material is removed by wiping.

  (6) The method for producing a surface-treated ceramic member according to (4) or (5) above, wherein the oxidation treatment is a heat treatment in a temperature range equal to or higher than a thermal decomposition temperature of the metal oxide precursor composition.

  (7) The method for producing a surface-treated ceramic member according to any one of (4) to (6), wherein the ceramic sintered body is an alumina sintered body.

  According to the present invention, the ceramic sintered body originally has a function, that is, excellent corrosion resistance, occurs during firing, grinding, etc., and remains in a minute space such as a pore on the surface of the ceramic sintered body. Scattering of particles generated due to the generated fine particles or microcracks can be prevented. In particular, there is little scattering of particles even in a high temperature use environment of 250 ° C. or higher. Therefore, the surface-treated ceramic member of the present invention is optimally used for a member exposed to a high temperature atmosphere, a corrosive gas atmosphere, or a plasma atmosphere in, for example, a semiconductor device manufacturing apparatus, a liquid crystal display manufacturing apparatus, and the like.

Test No. SEM image of 1 An SEM image of a surface-treated ceramic having a sol-gel film that has been coated with a silicon alkoxide compound on an alumina substrate having a porosity of 0.1%, wiped with a waste cloth, and then completed and cured by heating. Test No. 4 SEM image Test No. 5 SEM image Test No. 15 SEM images Test No. 4 SEM images and corresponding EPMA images (Si and Al)

1. Base material (ceramic sintered body)
As the ceramic sintered body, in order to express the original chemically stable function, a ceramic sintered body having a fine structure with a porosity of 1% or less is used. This is because if the porosity exceeds 1%, the mechanical properties and corrosion resistance deteriorate. Further, in the case of a ceramic sprayed coating, it is more porous than a sintered body that is densely sintered, and has a low mechanical strength and a large specific surface area, and therefore has poor corrosion resistance. For this reason, since it is a material which easily generates particles due to degranulation, it cannot be used for the surface-treated ceramic member of the present invention. Further, the metal oxide precursor composition left in the pores may be granulated in the course of heat treatment and cause generation of particles.

  The ceramic material used in the present invention is not particularly limited, and general ceramic materials such as alumina, yttria, zirconia, mullite, cordierite, silicon carbide, silicon nitride, aluminum nitride, and sialon can be used. Among these, it is particularly desirable to use alumina, aluminum nitride, yttria, etc., which are excellent in corrosion resistance and heat resistance.

  There is no restriction | limiting in particular in the manufacturing method of a ceramic sintered compact, What is necessary is just to employ | adopt a general manufacturing method. For example, after adding a known molding binder to a powder raw material having an average particle diameter of about 0.01 to 1 μm and granulating it by a known method such as a spray drying method, a die press, CIP (cold isostatic pressing) ) Can be produced by firing. A known sintering aid may be added to the powder raw material as necessary. At this time, an atmospheric furnace can be used as long as it is an oxide-based ceramic. For non-oxide ceramics, an atmosphere firing furnace such as nitrogen or argon can be used in addition to a vacuum furnace.

2. Film (oxide)
The surface-treated ceramic member of the present invention is obtained by forming an oxide film on the surface of a base material made of the ceramic sintered body. This oxide film can be obtained, for example, by applying a metal oxide precursor composition to a substrate and drying it, followed by heat treatment. The metal oxide precursor composition is not particularly limited as long as it can be converted into an oxide by heat treatment, but from the viewpoint of workability, a metal oxide precursor composition that is liquid at the time of application is preferable.

  For example, a MOD (Metal Organic Decomposition, organic metal) material can be used. The MOD material is a solution in which a metal organic compound is dissolved in an organic solvent. This MOD material is a material that forms an oxide film by performing heat treatment after application to a substrate and drying. Moreover, liquid silicone rubber, sol-gel material, etc. can also be used as a metal oxide precursor composition. The liquid silicone rubber is particularly preferably low-viscosity or can be applied by diluting with a solvent. The sol-gel material here is a compound obtained by hydrolyzing and polymerizing a metal alkoxide compound, a metal alkoxide or the like, and it is desirable to select a liquid compound. Moreover, with respect to the sol-gel material, the polymerization reaction may be controlled or a solvent may be added so as to obtain a property suitable for application to and penetration into the base material. This sol-gel material is also a material that forms an oxide film by performing heat treatment at a temperature equal to or higher than the thermal decomposition temperature after application to a substrate and drying.

  The oxide film is selectively embedded in recesses (gap between crystal grain boundaries, micropores, processing flaws, etc.) existing on the surface exposed to the processing atmosphere in at least a semiconductor manufacturing apparatus of a ceramic sintered body, It is necessary that the ceramic sintered body is formed so as to be exposed at portions other than the recesses, and the surface of the ceramic sintered body is mixed with the surface of the ceramic sintered body substrate and the surface of the oxide film. Here, the processing atmosphere includes a processing gas atmosphere (such as a corrosive gas such as argon gas, hydrogen gas, and halogen), a plasma atmosphere, and a vacuum atmosphere during heat treatment.

  This is because, as described above, fine particles or the like remain in the concave portions of the ceramic sintered body, and microcracks may be formed in the firing step, the processing step, or the like. The above oxide film selectively covers the recesses, captures the fine particles present therein, prevents scattering, and plays a role in preventing the falling off of the fine pieces caused by the microcracks. In particular, when the recesses on the surface of the ceramic sintered body substrate are selectively covered with an oxide film, it is possible to suppress the scattering of particles even in a high temperature use environment of 250 ° C. or higher.

  On the other hand, the ceramic sintered body excellent in corrosion resistance is exposed. The surface on which this ceramic sintered body is exposed is a smooth part that is originally free of dents. Therefore, it is easy to remove fine particles by washing, etc., and particles are not easily generated. It is a part that should exhibit its original function.

  In order to mix the substrate surface and the oxide film surface on the treated surface, for example, a coating liquid composed of the above-mentioned metal oxide precursor composition or the like is applied to the ceramic sintered body substrate, and this is completely Before curing, it is useful to wipe off with a waste cloth, dry and cure, and then oxidize by performing an oxidation treatment. This operation is effective even once, but it is more desirable to perform this operation twice or more. The substrate surface may be a ground surface, a fired surface, a heat-treated surface, a blast surface, or the like.

  Here, on a relatively smooth surface (fine particles are unlikely to remain on this surface), the coating solution can be easily removed, but the coating solution remains in the recesses (such as pores). And after the coating liquid remaining in the recesses is dried and cured, the coating liquid is oxidized and firmly bonded to the wall surface in the recesses, so that it does not fall off and is used at a high temperature of 250 ° C. or higher. It is possible to suppress scattering of particles even in the environment.

  Although there is no restriction | limiting in particular about the conditions of an oxidation process, It is preferable to carry out in the temperature range more than the thermal decomposition temperature of a metal oxide precursor composition. The heat treatment is preferably performed in a temperature range of 1500 ° C. or higher. This is because the effect of preventing the scattering of particles by integrating the base material and the film is further enhanced. If the heat treatment is performed at a temperature higher than the temperature at which the base material is thermally etched, the bond between the base material and the film is strengthened, and the effect of preventing particle scattering is further enhanced.

  Various ceramic base materials (surface roughness Ra: 0.7 ± 0.1 μm, dimensions: 30 mm × 30 mm × 2.5 mm) having the materials and porosity listed in Table 1 were prepared and used as test pieces. A coating material was applied to some test pieces. About some test pieces, the apply | coated film | membrane material was wiped off with the waste cloth. Some test pieces were subjected to heat treatment. The conditions for preparing these test pieces are also shown in Table 1. About various test pieces, the peeling | exfoliation generation | occurrence | production state of the film | membrane and the generation | occurrence | production number of particles were calculated | required. The results are also shown in Table 1.

<Number of particles>
Each test piece is inserted into a beaker containing pure water, and the beaker is mounted in a tank equipped with an ultrasonic transmitter, and then ultrasonic waves of 104 kHz are loaded for 1 minute at room temperature, The number of particles scattered in water was measured with an in-liquid particle counter (measurement range: 0.5 to 20 μm), and the number of particles of 1 μm or more was determined. From the number of particles of the various test pieces obtained, test No. The relative ratio (hereinafter simply referred to as “particle relative ratio”) to 1 (an example in which alumina without a film having a porosity of 0.1%) was calculated.

<Pyrolysis convergence temperature>
Using a differential thermal balance (TG-DTA), the mass change (TG) and differential heat (DTA) when the coating material (oxide precursor) is heated to 1500 ° C. in an inert gas atmosphere are measured, A TG value (TG ₀ ) at 1500 ° C. is obtained, and a minimum temperature in a temperature range where the difference from TG ₀ is continuously within 1% is defined as a thermal decomposition convergence temperature.

[Test No. About 1-16]
In these examples, alumina having a porosity of 0.1% is used as the base material. Test No. No. 1 is an example in which no film is formed on the alumina base material and no heat treatment is performed.

  Test No. 2 and 3 are examples in which heat treatment was performed without forming a film on the alumina base material. Test No. In 2 and 3, the particle relative ratios are 0.451 and 0.203, respectively, and the particle prevention effect can be confirmed once.

Test No. Nos. 4 and 5 were coated with a SiO ₂ precursor composition (MOD material), then wiped off, and then subjected to heat treatment to convert to oxide, and the recesses on the surface of the substrate were selectively selected by the oxide film. This is an example of coating. Test No. 4 and 5, the particle relative ratios were 0.068 and 0.056, respectively. It had a particle prevention effect far superior to 2 and 3.

Test No. No. 6 is an example in which the SiO ₂ precursor composition (MOD material) was coated and then converted into an oxide by heat treatment without wiping. Test No. In No. 6, peeling of the film occurred, and the relative particle ratio became extremely large at 5.12.

Test No. Nos. 7 and 8 were coated with an Al ₂ O ₃ precursor composition (MOD material), then wiped off, and then subjected to a heat treatment to convert it into an oxide. This is an example of selective coating. Test No. 7 and 8, the relative particle ratios were 0.156 and 0.097, respectively. It had a particle prevention effect far superior to 2 and 3.

Test No. No. 9 is an example in which an Al ₂ O ₃ precursor composition (MOD material) is coated and then converted into an oxide by heat treatment without wiping. Test No. In No. 9, peeling of the film occurred, and the relative particle ratio was extremely large at 6.53.

  Test No. Nos. 10 and 11 were coated with a YAG precursor composition (MOD material), then wiped off, and then heat-treated to convert to oxides so that the recesses on the surface of the substrate were selectively formed by the oxide film. This is an example of coating. Test No. 10 and 11, the relative particle ratios are 0.107 and 0.062, respectively. It had a particle prevention effect far superior to 2 and 3.

  Test No. No. 12 is an example in which after the YAG precursor composition (MOD material) was coated, it was converted into an oxide by heat treatment without wiping. Test No. No. 12, peeling of the film occurred, and the particle relative ratio was extremely large at 6.34.

Test No. Nos. 13 and 14 were coated with a Y ₂ O ₃ precursor composition (MOD material), then wiped off, and then subjected to heat treatment to convert it into an oxide. This is an example of selective coating. Test No. 13 and 14, the particle relative ratios were 0.085 and 0.063, respectively. It had a particle prevention effect far superior to 2 and 3.

  Test No. No. 15 is an example in which after the YAG precursor composition (MOD material) is coated, it is converted into an oxide by heat treatment without wiping. Test No. In No. 15, peeling of the film occurred, and the particle relative ratio was extremely increased to 6.23.

Test No. 16, after coating a SiO ₂ —Al ₂ O ₃ precursor composition (MOD material) having a low thermal decomposition temperature, wiping was performed, and then heat treatment was performed to convert it into an oxide. In this example, the recess is selectively covered with an oxide film. Test No. 16 has a particle relative ratio of 0.122. It had a particle prevention effect far superior to 2 and 3.

[Test No. About 17-20]
These examples are described in Test No. This is an example in which alumina having a porosity (0.9% or 0%) different from 1 to 16 is used as a base material.

Test No. No. 17 is an example in which a film is not formed on an alumina base material having a porosity of 0.9% and heat treatment is not performed. 18, after coating the same alumina base material with a SiO ₂ precursor composition (MOD material), wiping was performed, and then heat treatment was performed to convert the oxide into oxides. This is an example of selective coating with a film. Test No. No. 18 has a particle relative ratio of 0.875 and test No. 1 using the same alumina substrate. Compared with 17 (particle relative ratio: 1.13), particle generation could be reduced.

Test No. No. 19 is an example in which a film is not formed on an alumina base material having a porosity of 0% and heat treatment is not performed. No. 20, after coating the same alumina base material with the SiO ₂ precursor composition (MOD material), wiping was performed, and then heat treatment was performed to convert it into an oxide. This is an example of selective coating with a film. Test No. No. 20 has a relative particle ratio of 0.083, and test No. 20 using the same alumina base material. Compared to 19 (particle relative ratio: 0.601), particle generation was reduced.

[Test No. About 21-25]
These examples are described in Test No. 1 to 20 are examples in which yttria having a different material is used as a base material.

Test No. No. 21 is an example in which no film is formed on the yttria base material having a porosity of 0.2%, and no heat treatment is performed. No. 22, the same yttria base material was coated with a SiO ₂ precursor composition (MOD material), then wiped off, and then heat-treated to convert it into an oxide, whereby the concave portion on the surface of the base material was oxidized. This is an example of selective coating with a film. 23, after coating the same yttria base material with the Y ₂ O ₃ precursor composition (MOD material), wiping was performed, and then heat treatment was performed to convert it into an oxide, thereby forming a recess on the base material surface. This is an example of selective coating with an oxide film. Test No. In Nos. 22 and 23, the relative particle ratios are 0.087 and 0.109, respectively. Compared with 21 (particle relative ratio: 1.05), particle generation could be reduced.

Test No. No. 24 is an example in which a film is not formed on a yttria base material having a porosity of 2.1% and heat treatment is not performed. 25, the same yttria base material was coated with a SiO ₂ precursor composition (MOD material), then wiped off, and then heat-treated to convert it into an oxide, whereby the recess on the surface of the base material was oxidized. This is an example of selective coating with a film. Test No. In No. 25, the relative particle ratio was 2.52. Even if the recesses on the surface of the substrate were selectively covered with the oxide film, the generation of particles could not be reduced if the porosity of the substrate was too large.

[Test No. About 26 and 27]
These examples are described in Test No. 1 to 20 are examples in which zirconia having a different material is used as a base material.

Test No. No. 21 is an example in which no film is formed on the yttria base material having a porosity of 0.2%, and no heat treatment is performed. 22, after the same alumina base material was coated with the SiO ₂ precursor composition (MOD material), wiping was performed, and then heat treatment was performed to convert the oxide into oxides. This is an example of selective coating with a film. 23, after coating the same alumina base material with the Y ₂ O ₃ precursor composition (MOD material), wiping was performed, and then heat treatment was performed to convert it into an oxide, so that the concave portions on the surface of the base material were formed. This is an example of selective coating with an oxide film. Test No. In Nos. 22 and 23, the relative particle ratios are 0.087 and 0.109, respectively. Compared with 21 (particle relative ratio: 1.05), particle generation could be reduced.

  In order to confirm the surface state of various test pieces, SEM images and EPMA images were taken for some of the test pieces.

  FIG. FIG. 2 shows an SEM image of the surface-treated ceramic obtained by applying a silicon alkoxide compound polymer sol-gel to an alumina substrate having a porosity of 0.1% and wiping it with a waste cloth. 4 and 5 are test Nos. SEM images of 4, 5 and 15 are shown, respectively. FIG. 4 shows an SEM image of 4 and an EPMA image (Si and Al) corresponding to the SEM image.

  As shown in FIGS. 1 and 2, the powder remains on the surface of the alumina substrate as it is, and the surface of the substrate is rough and fine protrusions may fall off during use of the apparatus. If a silicon alkoxide compound polymer sol-gel is applied to an alumina substrate having a porosity of 0.1% and then wiped off with a waste cloth, it covers powders and protrusions that may fall off. In such surface-treated ceramics, particles are hardly generated until the use environment is about 200 ° C., but as described above, the particles rapidly increase when the use environment is 250 ° C. or higher.

On the other hand, as shown in FIGS. 3 and 4, after coating the SiO ₂ precursor composition (MOD material), wiping is performed, and then heat treatment at 1500 ° C. or 1650 ° C. is performed to convert the oxide into an oxide. For example, the powder and protrusions present on the alumina substrate were completely covered, and the film was integrated with the substrate. Further, in the example in which heat treatment was performed at 1650 ° C., the base material was subjected to thermal etching, and the bond between the oxide film and the base material was further strengthened.

  As shown in FIG. 5, even if the heat treatment at 1650 ° C. is performed, if the coating material is not wiped off, the concave portions on the surface of the base material cannot be selectively covered with the oxide film, and the surface is derived from the coating material. Many protrusions occurred. This protrusion is expected to easily fall off and scatter in the usage environment of the apparatus.

As shown in FIG. 6, it can be seen that Si is present in a portion corresponding to the concave portion on the surface of the substrate. That is, in the surface-treated ceramic member that has been coated with the SiO ₂ precursor composition (MOD material), then wiped off, and then converted into an oxide by heat treatment, the recesses on the substrate surface are covered with the oxide film. It can be seen that it is selectively coated.

  According to the present invention, the ceramic sintered body originally has a function, that is, excellent corrosion resistance, occurs during firing, grinding, etc., and remains in a minute space such as a pore on the surface of the ceramic sintered body. Scattering of particles generated due to the generated fine particles or microcracks can be prevented. In particular, there is little scattering of particles even in a high temperature use environment of 250 ° C. or higher. Therefore, the surface-treated ceramic member of the present invention is optimally used for a member exposed to a high temperature atmosphere, a corrosive gas atmosphere, or a plasma atmosphere in, for example, a semiconductor device manufacturing apparatus, a liquid crystal display manufacturing apparatus, and the like.

Claims (7)

A ceramic member having a film-forming surface on at least a part of a ceramic sintered body substrate having a porosity of 1% or less,
A surface-treated ceramic member, wherein a concave portion on the surface of a ceramic sintered body is selectively covered with an oxide film.   2. The surface-treated ceramic member according to claim 1, wherein the oxide film is a film converted into an oxide by performing a heat treatment after coating the metal oxide precursor composition. 3.   The surface-treated ceramic member according to claim 1, wherein the surface-treated ceramic member is used in a semiconductor or electronic device manufacturing apparatus.   A coating material composed of a metal oxide precursor composition is applied to the surface of a ceramic sintered body substrate having a porosity of 1% or less, and the coating material is applied to the recesses on the surface of the ceramic sintered body substrate before curing. A method for producing a surface-treated ceramic member, comprising: removing a part of the coating material under conditions such that it remains, curing the coating material, and then oxidizing the coating material. The method for producing a surface-treated ceramic member according to claim 4, wherein part of the coating material is removed by wiping.   The method for producing a surface-treated ceramic member according to claim 4 or 5, wherein the oxidation treatment is a heat treatment in a temperature range equal to or higher than a thermal decomposition temperature of the metal oxide precursor composition.   The method for producing a surface-treated ceramic member according to any one of claims 4 to 6, wherein the ceramic sintered body is an alumina sintered body.

Images