JP2022152706A - Yag sintered compact and manufacturing method thereof - Google Patents

Abstract

To provide a YAG sintered compact which can suppress particle dusting even when used in a plasma environment and has a high plasma resistance, and to provide a manufacturing method thereof.SOLUTION: A YAG sintered compact has an average particle diameter of 8 μm or more and 15 μm or less, and a ratio of the number of pores inside the particle to the number of all the pores within a cut face of 70% or more. By setting the particle diameter within a predetermined range, detachment of particles due to plasma corrosion hardly occurs. In addition, by setting a ratio of the number of pores inside the particle to the number of all the pores within the cut face to 70% or more, the plasma erosion from the pore hardly occurs. As a result, particle dusting is suppressed even when used in a plasma environment, which results in a YAG sintered compact having a high plasma resistance.SELECTED DRAWING: Figure 1

Description

The present invention relates to a YAG sintered body and its manufacturing method.

Conventionally, a _{Y3Al5O12 ( YAG} ) sintered body having good plasma resistance has been used as a semiconductor device member, particularly a member used in a plasma environment.

Patent Document 1 discloses a gas nozzle used in a plasma apparatus, which includes a columnar body made of a ceramic sintered body having a through hole through which gas flows, and one end face of the body is provided with a nozzle for the gas in the through hole. and the inner wall of the through hole has a first region located near the outflow port and a second region located inside the main body rather than the first region, and A gas nozzle is disclosed in which the first region and the second region are made of the quenched surface of the ceramic sintered body, and the average crystal grain size in the first region is larger than the average crystal grain size in the second region. there is

Further, Patent Document 2 includes a substrate made of ceramics containing aluminum nitride as a main component and having a sample holding surface on the outer surface thereof, and a conductor provided inside the substrate facing the sample holding surface. and the oxygen content in the ceramics is lower in the region located inside the outer periphery of the conductor than in the region located outside the outer periphery of the conductor, in the sample holding surface side of the conductor in the inside of the substrate, A sample holder is disclosed in which the grain size of the ceramics located near the conductor is larger than the grain size of the ceramics on the sample holding surface. Patent Document 2 discloses that the grain size of the ceramics in the vicinity of the electrostatic adsorption electrode in the low-oxygen region is preferably larger than the grain size of the ceramics on the sample holding surface, and that the grain size on the sample holding surface should be made smaller. It is possible to improve the strength of the sample-holding surface by holding the sample-holding surface, and cracks may occur in the sample-holding surface. It is stated that the applied force is dispersed through grain boundaries and the length of fine cracks is proportional to the grain size of the ceramics.

Japanese Patent No. 6046752 Japanese Patent No. 6093010

Ceramic sintered bodies can be produced by sintering the raw material powder itself or the calcined powder with or without a sintering aid, or by reaction sintering to create a sintered body through a reaction during sintering to reduce costs. manufactured by law. The particle size of the sintered body is affected by its manufacturing method.

If the particle diameter of the surface layer portion of the sintered body is large, the particles are likely to be detached due to plasma corrosion. In addition, it has been a cause of particle dust generation that lowers the production yield of semiconductors and the like. Furthermore, the number of pores (denseness of the sintered body) and the position of the pores also affect particle generation.

However, plasma resistance is chemical resistance, and the characteristics change greatly depending on the constituent composition. Patent Document 1 describes ceramics in general terms, and Patent Document 2 describes only AlN ceramics. However, with respect to YAG ceramics, which are considered promising as a plasma-resistant material, the relationship between the manufacturing method and plasma resistance has not been clarified from the above literature.

Therefore, there has been a demand for a YAG sintered body that suppresses particle dusting even when used in a plasma environment and has higher plasma resistance than ever before.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a YAG sintered body that suppresses particle dust generation even when used in a plasma environment and has high plasma resistance, and a method for producing the same. and

(1) In order to achieve the above object, the YAG sintered body of the present invention is a YAG sintered body having an average particle size of 8 μm or more and 15 μm or less, and It is characterized in that the ratio of the number of pores to be formed is 70% or more.

Thus, when the average particle diameter is within a predetermined range, detachment of particles due to plasma corrosion is less likely to occur. In addition, when the ratio of the number of pores present in the grains to the pores on the cut surface is 70% or more, plasma erosion from the pores is less likely to occur. As a result, even when used in a plasma environment, particle dust generation is suppressed, and the YAG sintered body has high plasma resistance.

(2) In addition, the YAG sintered body of the present invention is characterized in that the average particle size of the surface layer of the sintered body is smaller than the average particle size of the inside of the sintered body on the cross section.

In this way, by making the average particle size of the surface layer of the YAG sintered body smaller than that of the inside, even if particles detach from the surface, they are easily discharged outside the process space, and the particles adhere to the substrate. can be minimized.

(3) In addition, the YAG sintered body of the present invention is characterized in that the number of pores per unit area of the surface layer of the sintered body is smaller than the number of pores per unit area inside the sintered body on the cut surface. .

As a result, the surface structure has fewer pores than the internal structure and becomes a dense structure. Therefore, the generation of particles is suppressed, and the plasma resistance of the YAG sintered body is further increased.

(4) In addition, in the YAG sintered body of the present invention, the average particle size of the surface layer of the sintered body and the average particle size of the inside of the sintered body at the cut surface are substantially the same, and the pores existing in the grains are substantially the same. The number ratio is 80% or more, and the relative density is 97% or more.

As a result, the structure of the surface and the inside is uniform, and many of the pores are present in the grains, so the surface is resistant to damage such as cracks due to disturbances such as thermal loads, and is stable. Dust generation itself is suppressed.

(5) Further, the method for producing a YAG sintered body of the present invention is a method for producing a YAG sintered body, comprising the steps of: weighing Y oxide powder and Al oxide powder; a step of adding a binder to the powder and mixing; a step of granulating the mixed powder to form a granulated powder; a step of molding the granulated powder to form a compact; and sintering in an environment in which the YAG calcined body exists in a furnace.

In this way, by sintering in an environment where the YAG calcined body is present together with the compact in the furnace, it is possible to adjust the reaction with the gas phase on the surface during reactive sintering. A YAG sintered body described in (4) can be produced. In addition, it can be produced at a lower cost than the conventional production method in which the YAG calcined powder is once synthesized, then molded and fired.

According to the present invention, it is possible to form a YAG sintered body that suppresses particle generation even when used in a plasma environment and has high plasma resistance. Also, such a YAG sintered body can be produced.

1 is a schematic cross-sectional view showing a usage example of a YAG sintered body according to an embodiment of the present invention; FIG. 4 is a table showing the results of each test of Examples and Comparative Examples. 3(a) and 3(b) are optical microscope photographs of the surface layer and the inside of the sintered body of Example 1, respectively.

Next, an embodiment of the invention will be described. In addition, in the configuration diagram, the size of each component is conceptually represented, and does not necessarily represent the actual size ratio.

[Structure of YAG sintered body]
(First embodiment)
The YAG sintered body of the present invention consists of _{Y3Al5O12 ( YAG} ) crystals. Consisting of YAG crystal means that the YAG phase is confirmed by XRD (X-ray diffractometer) method and other phases are substantially absent, for example, 1% or less in a simple quantitative method such as RIR method.

The YAG sintered body of the present invention has an average particle size of 8 µm or more and 15 µm or less. Thus, when the average particle diameter is within a predetermined range, detachment of particles due to plasma corrosion is less likely to occur. The average particle diameter can be, for example, the average value of the values calculated by the intercept method after photographing in a 1000-fold field of view of an optical microscope. The average particle size can be obtained by randomly observing three fields of view so as to obtain the overall value of the YAG sintered body. Since the YAG sintered body of the present invention may have different average particle sizes depending on the depth from the surface, the overall average particle size is measured with images at different depths from the surface, and the average value is used. is preferred. Moreover, when obtaining the average particle size of a predetermined area, the surface satisfying the condition is measured.

For example, when obtaining the average particle size of the surface layer of the sintered body, an image taken on the surface of the sintered body is used. The surface layer of the sintered body is a range within 2.5 mm from the surface of the sintered body. Since the present invention may be characterized by the presence or absence of a difference in structure between the surface layer and the internal structure of the YAG sintered body, it is preferable that the surface layer of the sintered body is as close to the surface of the sintered body as possible. Therefore, when the surface of the sintered body is a polished surface, the surface of the sintered body may be measured as the surface layer. Moreover, when the surface of the sintered body cannot be obtained with an average particle size such as a quenched surface, the surface of the sintered body which has been polished by about 500 μm may be measured as the surface of the surface layer of the sintered body.

Further, for example, when obtaining the average particle diameter inside the sintered body, an image taken in a field of view including points inside the sintered body is used. A point inside the sintered body is defined as a point that is separated from the surface of the sintered body by 5 mm or more on a cross section obtained by cutting the sintered body perpendicularly to the surface.

In the YAG sintered body of the present invention, the ratio of the number of pores present in the grains among the pores on the cut surface is 70% or more, preferably 80% or more, more preferably 85% or more. preferable. Thus, when the ratio of the number of pores present in the grain to the pores on the cut surface is 70% or more, plasma erosion from the pores is less likely to occur. As a result, even when used in a plasma environment, particle dust generation is suppressed, and the YAG sintered body has high plasma resistance.

For example, the pores of the sintered body are photographed with an optical microscope at a magnification of 1000 times, and the free software "ImageJ" developed by the National Institute of Health (NIH) is used. Then, a field of view of 100 μm×100 μm randomly determined from photographed image data is binarized, and the pores can be determined. In addition, as for the measurement points, three fields of view may be observed at random.

Also, the ratio of pores present in the grain is binarized using a different threshold value in the same visual field as the visual field in which the pores were determined, and the boundaries of the grains are determined. Then, the pores surrounded by the boundaries of the grains are defined as the pores existing within the grains (intragranular pores), and the pores at the triple points of the grains are defined as the pores existing at the grain boundaries (grain boundary pores). can be done. Also in the measurement of pores, when the number of pores in a predetermined region or the ratio of pores existing in grains is obtained, the measurement is performed on the surface that satisfies the conditions.

In the YAG sintered body according to the present embodiment, it is preferable that the average particle size of the surface layer of the sintered body is smaller than the average particle size of the inside of the sintered body at the cross section. In this way, by making the average particle size of the surface layer of the YAG sintered body smaller than the average particle size of the inside, even if particles detach from the surface, they are easily discharged outside the process space, and the particles are transferred to the substrate. adhesion can be minimized.

In the YAG sintered body of the present invention, the number of pores per unit area of the surface layer of the sintered body is preferably smaller than the number of pores per unit area inside the sintered body on the cross section. As a result, the surface structure has fewer pores than the internal structure and becomes a dense structure. Therefore, the generation of particles is suppressed, and the plasma resistance of the YAG sintered body is further enhanced.

The YAG sintered body of the present invention preferably has a relative density of 95.0% or more, more preferably 97.0% or more, even more preferably 98.0% or more. This is because YAG sintered bodies tend to have higher plasma resistance when the relative density is higher. The relative density of the YAG sintered body can be determined by the Archimedes method.

The YAG sintered body preferably has a total content of metals other than Y and Al of 100 ppm or less. By sufficiently reducing the total content of metals other than Y and Al in this manner, the risk of inclusion of crystals or metals other than YAG in the YAG sintered body can be sufficiently reduced. If the YAG sintered body contains crystals or metals other than YAG, there is a high possibility that plasma corrosion will start there. For example, when SiO ₂ is included, corrosion resistance to fluorine-based plasma is lowered. It should be noted that the YAG sintered body preferably has a low content of elements other than Y, Al, and O, not limited to metals.

The content of Y and Al in terms of oxides in the YAG sintered body and the content of metals other than Y and Al contained in the YAG sintered body were determined by WDX (Wavelength Dispersive X-ray spectroscopy). ) can be measured by

(Second embodiment)
In the YAG sintered body according to the present embodiment, the preferable relationship between the average particle size of the surface layer of the sintered body and the average particle size of the inside of the sintered body at the cut surface is different from that of the first embodiment, It is a YAG sintered body similar to that of the first embodiment. Therefore, definitions of terms other than the preferred relationship between the average particle size of the surface layer of the sintered body and the average particle size of the inside of the sintered body on the cut surface of the first embodiment, the preferred range, the measurement method, etc. are all the same. It can also be applied to the YAG sintered body according to the embodiment.

In the YAG sintered body according to the present embodiment, it is preferable that the average particle size of the surface layer of the sintered body and the average particle size of the inside of the sintered body at the cross section are substantially the same. That the average particle size of the surface layer of the sintered body and the average particle size of the inside of the sintered body at the cut surface are substantially the same means that the average particle size of the surface layer of the sintered body and the average inside The difference from the particle size shall be within ±20% based on the internal average particle size.

As a result, the structure of the surface and the inside is uniform, and many of the pores are present in the grains, so the surface is resistant to damage such as cracks due to disturbances such as thermal loads, and is stable. Dust generation itself is suppressed.

The YAG sintered body according to the first embodiment and the YAG sintered body according to the second embodiment of the present invention suppress particle dust generation even when used in a plasma environment, and have high plasma resistance. is the body. It should be noted that the features of the first embodiment and the features of the second embodiment may be mixed in members used in actual products using the YAG sintered body of the present invention. That is, a member using the YAG sintered body of the present invention also has a part having the features of the first embodiment and another part having the features of the second embodiment. It can be said that The reason is that the YAG sintered body according to the second embodiment is obtained by cutting the surface layer of the YAG sintered body according to the first embodiment.

[Usage example of YAG sintered body]
Next, an example of using the YAG sintered body of the present invention will be described. FIG. 1 is a schematic cross-sectional view showing a usage example of a YAG sintered body according to an embodiment of the present invention. The YAG sintered body of the present invention is used, for example, in a semiconductor manufacturing process or a liquid crystal manufacturing process, in a film forming apparatus for forming a thin film on a substrate W such as a semiconductor wafer or a glass substrate, or for performing fine processing on the substrate W. is used as a gas nozzle 10 for use in a plasma apparatus 100 such as an etching apparatus.

For example, in the film forming apparatus, a raw material gas containing a corrosive gas is introduced into the reaction vessel 20 using the gas nozzle 10, and plasma CVD (Chemical Vapor Deposition) is used to transform the raw material gas into plasma. , may form a thin film on the substrate W. Further, in the etching apparatus, a halogen-based corrosive gas as a raw material gas is introduced into the reaction vessel 20 using the gas nozzle 10, and the corrosive gas is turned into plasma to form an etching gas, thereby performing fine processing on the substrate W. may apply.

The gas nozzle 10 has a gas supply port 11 to which a gas such as a corrosive gas is supplied from a gas supply unit (not shown), a gas discharge port 12 to discharge the gas into the reaction vessel 20, and the gas supply port 11 and the gas discharge port 12. It has a nozzle hole 13 communicating with.

The YAG sintered body according to the embodiment of the present invention is a member having a portion exposed to corrosive gas. The part is a member that constitutes at least part of the part exposed inside the reaction vessel 20 . However, the YAG sintered body may constitute the entire gas nozzle 10 . Moreover, the YAG sintered body may be, for example, the container body 21 or the lid portion 22 constituting the reaction container 20, or may be a part thereof.

[Manufacturing method of YAG sintered body]
Next, an example of the method for producing the YAG sintered body of the present invention will be described. First, an oxide of Y and an oxide of Al are prepared as raw material powders for a ceramic sintered body. The oxide of Y is preferably Y ₂ O ₃ and the oxide of Al is preferably Al ₂ O ₃ , but a material that becomes YAG after sintering in an air atmosphere may be used. The purity of each powder is preferably 99.9% or higher, more preferably 99.99% or higher. Moreover, the average particle size of each powder is preferably 0.1 μm or more and 2.0 μm or less.

Next, each powder is weighed so that the YAG sintered body after sintering will have a predetermined composition ratio in terms of oxide. The predetermined composition ratio is a composition in which Y is 37.5 mol% in terms of oxide (Y ₂ O ₃ ) and Al is 62.5 mol% in terms of oxide (Al ₂ O ₃ ) in the sintered body after firing. be. A deviation of about 1.0 mol % is allowed, but it is preferable that the composition ratio is as close to the predetermined composition ratio as possible.

Next, the raw material powders are mixed. Each powder is put into a ball mill, for example, together with PVA as a solvent, and ground and mixed. A ball mill can use, for example, alumina balls. Mixing time can be, for example, 20 hours.

The slurry is then dried and granulated. As a method for obtaining a granulated powder from a slurry, for example, a method of drying the slurry while boiling it in hot water to remove the solvent from the slurry to obtain a powder, and passing the obtained powder through a sieve may be mentioned. can. A spray dryer can also be used.

Next, the granulated powder is molded. The obtained granulated powder is molded by a press to obtain a compact. As a molding method, press molding, CIP, hot press, HIP, or the like can be used. In addition, the molding pressure can be set to 98 MPa, for example, in the case of press molding.

Next, the compact is fired in an environment in which the YAG calcined body exists in a furnace. The environment in which the YAG calcined body exists in the furnace means that the calcined body and the sintered body already having the composition of YAG exist in the furnace in addition to the molded body to be fired.

In this way, by sintering in an environment where the YAG calcined body is present together with the molded body in the furnace, it is possible to adjust the reaction with the gas phase on the surface during reactive sintering, and use it in a plasma environment. It is possible to produce a YAG sintered body that suppresses particle dusting and has high plasma resistance. In addition, it can be produced at a lower cost than the conventional production method in which the YAG calcined powder is once synthesized, then molded and fired.

The firing conditions may be the conditions of existing methods. For example, by firing at a temperature of 1700° C. for 1 hour or longer in an air atmosphere, the compact can be fired to obtain a sintered body. A step of pressurizing the sintered body using HIP and densifying it may be provided.

Further, a step of grinding or polishing the surface layer of the YAG sintered body may be provided to such an extent that the average particle size of the surface layer of the sintered body and the average particle size of the inside of the sintered body at the cut surface are substantially the same.

Through such a process, it is possible to produce a YAG sintered body that suppresses particle dusting even when used in a plasma environment and has high plasma resistance.

[Examples and Comparative Examples]
(Method for preparing test pieces of Examples 1 and 2)
_{Y 2} O _{3 raw} material powder ₍ purity _99.9 %, average particle size 1 μm) and Al ₂ O ₃ raw material powder (purity 99.99%, average particle size 0.5 μm) were weighed. Next, 2 wt % of a binder (PVA) was added to the weighed raw material powder, mixed, and granulated. After that, uniaxial press molding was carried out. Then, the compact was placed in an alumina sagger and fired in an air atmosphere furnace at 1700° C. for 10 hours to prepare a test piece. In Example 1, a YAG calcined body was put in the sheath in addition to the molded body. In Example 2, the YAG calcined body was put in the sheath in addition to the molded body, but the amount thereof was about half of that in Example 1.

(Method for preparing test piece of Comparative Example 1)
_{Y 2} O _{3 raw} material powder ₍ purity _99.9 %, average particle size 1 μm) and Al ₂ O ₃ raw material powder (purity 99.99%, average particle size 0.5 μm) were weighed. Next, 2 wt % of a binder (PVA) was added to the weighed raw material powder, mixed, and granulated. The granulated powder was fired in an air atmosphere furnace at 1700° C. for 10 hours to prepare YAG calcined powder.

This was pulverized with a ball mill to prepare a YAG raw material powder having an average particle size of 3 μm. 2 wt % of a binder (PVA) was added to the produced YAG raw material powder, mixed and granulated. After that, uniaxial press molding was carried out. Then, the compact was placed in an alumina sagger and fired in an air atmosphere furnace at 1700° C. for 10 hours to prepare a test piece.

(Evaluation method)
The average particle size, number of pores, relative density, and plasma resistance of each test piece were measured and evaluated by the following tests. The size of each specimen is □30 mm×15 mm. FIG. 2 is a table showing the results of each test of Examples and Comparative Examples.

(Average particle size)
The surface layer of the sintered body of each test piece, the inside of the sintered body at the cut surface, and the structure at the predetermined position of the cut surface are photographed with a field of view of an optical microscope of 1000 times, and the average value of the values calculated by the intercept method is calculated. It was taken as the average particle size of each region or the whole. As for the surface layer of the sintered body, the quenched surface was polished to a thickness of 500 μm and photographed at three locations at random. For the inside of the sintered body on the cut plane, points separated by 5 mm or more from the surface of three different cut planes cut perpendicularly to the surface were selected at random, and a field of view including those points was photographed. As the predetermined position of the cut plane, the point directly below the surface of the three cut planes cut perpendicular to the surface, the center of the cut plane, and the center of the cut plane and the midpoint of the surface were selected, and the image was taken in a field of view including each point. .

(number of pores)
The surface layer of the sintered body of each test piece and the internal structure of the sintered body at the cut surface are photographed with an optical microscope field of view of 1000 times, and a field of view of □ 100 μm (100 μm × 100 μm square) is randomly selected at three locations. Photographs were taken, and the average value of the number of pores was taken as the number of pores. As for the surface layer of the sintered body, the quenched surface was polished to a thickness of 500 μm and photographed at three locations at random. For the inside of the sintered body on the cut plane, points separated by 5 mm or more from the surface of three different cut planes cut perpendicularly to the surface were selected at random, and a field of view including those points was photographed. The values shown in the table of FIG. 2 are rounded off average values.

(relative density)
The bulk density of the sintered body was measured by the Archimedes method, and the relative density was calculated from the theoretical density. A test piece having a relative density of 95% or more is dense as a sintered body. When it is dense like this, it can be suitably used as a member for a large-sized semiconductor manufacturing apparatus.

(Plasma resistance)
After mirror-polishing one side of the test piece and masking a part of it with polyimide tape, the test piece was placed in a parallel plate type RIE etching apparatus in a vacuum chamber and exposed to CF ₄ +20% O ₂ plasma for 10 hours. and measured the corrosion resistance depth. A corrosion resistance depth of 1 μm or less was evaluated as good (∘), and a greater depth was evaluated as poor (x).

(Evaluation results)
As for the average particle sizes of Examples 1 and 2, the average particle size of the surface layer of the sintered body was smaller than the average particle size of the inside of the sintered body. In contrast, in Comparative Example 1, the average particle size of the surface layer of the sintered body was slightly larger than the average particle size of the inside of the sintered body.

Moreover, in Examples 1 and 2, the number of pores in the surface layer of the sintered body was smaller than the number of pores inside the sintered body. On the other hand, in Comparative Example 1, the number of pores in the surface layer of the sintered body was slightly larger than the number of pores inside the sintered body. In addition, the ratio of the number of intragranular pores to the total number of pores in Examples 1 and 2 (the sum of the number of surface pores and the number of internal pores) was generally high, and was 75% or more in any of the Examples. there were. 3(a) and 3(b) are optical microscope photographs of the surface layer and the inside of the sintered body of Example 1, respectively.

Moreover, as shown in FIGS. 3(a) and 3(b), most of the pores inside the sintered bodies of Examples 1 and 2 were intragranular pores, and grain boundary pores were seen closer to the surface layer. . Due to such characteristics, when the surface layer is polished to a certain degree, the grain boundary pores are reduced, so it is considered that the plasma resistance is further improved.

On the other hand, in Comparative Example 1, the proportion of intragranular pores was small, and most of them were grain boundary pores. Therefore, when compared at the same relative density, the YAG sintered bodies of Examples are considered to have higher plasma resistance than the YAG sintered bodies of Comparative Examples.

It is considered that, in all of the examples, the reaction between Al ₂ O ₃ and Y ₂ O ₃ made the grain boundaries more wettable, which made it difficult for pores to form at the grain boundaries. On the other hand, in the comparative example, sintering is performed by volume diffusion of YAG particles, and it is considered that pores tend to remain at the triple points between particles.

The relative densities of Examples 1 and 2 were 97% or more and were dense. Moreover, both Examples 1 and 2 were in a good range in the evaluation of plasma resistance.

(Example 3)
A sintered body of Example 3 was obtained by grinding and polishing the surface layer of the sintered body produced under the same conditions as in Example 1 to a thickness of 500 μm. This is because the small particle size region of Example 1 was about 500 μm from the surface. The average particle size of the new surface was 11.3 μm, and the average particle size of the inside of the sintered body at the cut surface was 12.8 μm. That is, it can be said that the average particle size of the surface layer of the sintered body of Example 3 and the average particle size of the inside of the sintered body at the cross section are substantially the same.

Moreover, the number of pores per unit area of the surface layer of the sintered body was 42, and the number of pores per unit area inside the sintered body on the cross section was 40, showing almost no difference. As a result, it was found that the YAG sintered body from which the surface layer of the sintered body was removed by a predetermined thickness was a sintered body with extremely homogeneous distribution of particle diameters and pores as a whole. Also, the plasma resistance of Example 3 was good.

In addition, the thickness in the range where the average particle diameter differs greatly can be adjusted by the manufacturing conditions, and was about 500 μm in Example 1, but was about 2.5 mm in Example 2.

From the above results, it was confirmed that the YAG sintered body of the present invention is a YAG sintered body that suppresses particle dust generation even when used in a plasma environment and has high plasma resistance. It was also confirmed that the method for producing a YAG sintered body of the present invention can produce such a YAG sintered body.

It should be noted that the present invention is not limited to the above embodiments, and can be modified as appropriate without departing from the scope of the invention.

10 gas nozzle 11 gas supply port 12 gas discharge port 13 nozzle hole 20 reaction container 21 container main body 22 lid portion 100 plasma device W substrate

Claims (5)

YAG sintered body,
The average particle size is 8 μm or more and 15 μm or less,
A YAG sintered body, wherein 70% or more of the pores in the cut surface are present in grains. 2. The YAG sintered body according to claim 1, wherein the average particle size of the surface layer of the sintered body is smaller than the average particle size of the inside of the sintered body on the cut surface. 3. The YAG sintered body according to claim 1 or 2, wherein the number of pores per unit area of the surface layer of the sintered body is smaller than the number of pores per unit area inside the sintered body on the cut surface. . The average particle size of the surface layer of the sintered body and the average particle size of the inside of the sintered body at the cut surface are substantially the same,
The ratio of the number of pores present in the grains is 80% or more,
2. The YAG sintered body according to claim 1, having a relative density of 97% or more. A method for producing a YAG sintered body,
weighing Y oxide powder and Al oxide powder;
adding a binder to the weighed powder and mixing;
granulating the mixed powder to form a granulated powder;
a step of molding the granulated powder to form a compact;
and firing the compact in an environment in which the YAG calcined body exists in a furnace.

Images