JP6950508B2 - Manufacturing method of electrode plate for plasma processing equipment and electrode plate for plasma processing equipment - Google Patents

Description

The present invention relates to an electrode plate for a plasma processing apparatus and a method for manufacturing an electrode plate for a plasma processing apparatus.

Plasma processing devices such as plasma etching devices and plasma CVD devices used in the semiconductor device manufacturing process are provided with a pair of electrodes arranged so as to face each other in the vertical direction in a vacuum chamber. Generally, the upper electrode is formed with a ventilation hole for passing a gas for plasma generation, and the lower electrode is a gantry, and a substrate to be processed such as a wafer can be fixed. .. Then, while supplying gas for plasma generation from the ventilation holes of the upper electrode to the substrate to be processed fixed to the lower electrode, plasma is generated by applying a high frequency voltage between the upper electrode and the lower electrode. The substrate to be processed is configured to be subjected to processing such as etching.

In the plasma processing apparatus having the above configuration, the electrodes are gradually consumed by being irradiated with plasma during the etching process. Therefore, as an electrode, a SiC sintered body having high plasma resistance and excellent heat resistance is widely used. Further, a SiC sintered body is used as an electrode substrate, and a coating layer is provided on the surface of the electrode substrate to improve the plasma resistance of the electrode surface.

Patent Document 1 discloses that a dense silicon carbide layer is formed on the surface of an electrode (gas blowing plate) for a plasma etching apparatus on the side where a gas for plasma generation is ejected. In Patent Document 1, as the dense silicon carbide layer, SiC (CVD-SiC) formed by a chemical vapor deposition method (CVD method) and a sintered layer made of a dense silicon carbide sintered body are mentioned. Has been done.

Japanese Unexamined Patent Publication No. 2005-285845

In the electrode plate for a plasma processing apparatus in which a dense silicon carbide layer is formed on a SiC sintered body, there is a problem that the SiC sintered body and the dense silicon carbide layer may be peeled off during plasma treatment.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an electrode plate for a plasma processing apparatus in which the SiC sintered body and the dense silicon carbide layer are not easily peeled off, and a method for manufacturing the same. do.

In order to solve the above problems, the electrode plate for the plasma processing apparatus of the present invention _{includes a Y 2} O ₃ containing SiC sintered body containing _{Y 2} O ₃ and SiC and the _{Y 2} O ₃ containing SiC sintered body. a plasma processing apparatus for electrode plates and a dense silicon carbide layer that is provided on at least one surface of the Y ₂ O ₃ containing SiC sintered body, Y concentration 0.3 mass% or more 7 The Y concentration provided on at least one surface of the Y high-concentration sintered base material in the range of mass% or less and the Y high-concentration sintered base material is lower than that of the Y high-concentration sintered base material. It has a concentration sintered layer, the Y low concentration sintered layer has a thickness in the range of 1.0 mm or more and 1.9 mm or less, and the dense silicon carbide layer is on the Y low concentration sintered layer side. It is characterized by being provided on the surface.

In the electrode plate for a plasma processing apparatus having this configuration, _{a Y 2} O ₃ containing SiC sintered body containing _{Y 2} O ₃ and SiC is used _{as an electrode substrate, and the Y 2} O ₃ containing SiC sintered body has a high Y concentration. It has a sintered base material and a Y low-concentration sintered layer provided on at least one surface of the Y high-concentration sintered base material, and the Y high-concentration sintered base material has a Y concentration of 0.3 mass. % or more 7 located in the mass% or less, because it contains a relatively large amount of Y ₂ O ₃ which acts as a sintering aid, a dense intensity increases. Further, _{the Y low-concentration sintered layer of the Y 2} O _3- containing SiC sintered body has a lower Y concentration than the Y high-concentration sintered base material, and fine pores (micropores) are formed due to the lack of _{Y 2} O _3. As a result, the dense silicon carbide layer penetrates into the micropores, so that the bonding force between the Y low-concentration sintered layer and the dense silicon carbide layer is increased. Then, the Y low density sintered layer is in the range of less than 1.0mm 1.9mm or less in thickness, it is possible to enter the number of dense silicon carbide layer in the Y low density sintered layer, Y ₂ O _{It is possible to make it difficult for the 3-} containing SiC sintered body and the dense silicon carbide layer to peel off.

Here, in the electrode plate for the plasma processing apparatus of the present invention, the ratio of the Y concentration of the Y low concentration sintered layer to the Y high concentration sintered base material is preferably 0.2 or less.
In this case, Y in the low density sinter layers, since microporous by deficiency of Y ₂ O ₃ is formed a number, Y ₂ O ₃ and containing SiC sintered body and dense silicon carbide layer is peeled off more reliably It becomes difficult. Incidentally, Y concentration of Y-rich sintered substrate is Y concentration in the central portion in the thickness direction of the Y ₂ O ₃ containing SiC sintered body.

In the method for producing an electrode plate for a plasma processing apparatus of the present invention, on at least one surface of _{a Y 2} O ₃ containing SiC sintered body containing _{Y 2} O ₃ and SiC and the _{Y 2} O _{3 containing SiC sintered body.} A method for manufacturing an electrode plate for a plasma processing apparatus having a dense silicon carbide layer provided, which comprises a Y high-concentration sintered base material having a Y concentration in the range of 0.3% by mass or more and 7% by mass or less. The Y low-concentration sintered base material has a Y low-concentration sintered layer having a Y concentration lower than that of the Y high-concentration sintered base material provided on at least one surface of the Y high-concentration sintered base material. The layer is a dense silicon carbide layer on the surface of the Y low-concentration sintered layer of _{a Y 2} O _3- containing SiC sintered body having a thickness in the range of 1.0 mm or more and 1.9 mm or less by a chemical vapor phase growth method. It is characterized by having a step of forming.

In the method for manufacturing an electrode plate for a plasma processing apparatus having this configuration, the Y concentration is lower than that of the Y high concentration sintered base material, and the Y low concentration sintered layer in which micropores are formed due to the loss of _{Y 2} O _{3 is formed.} Since the dense silicon carbide layer is formed on the surface by the chemical vapor deposition method, the dense silicon carbide layer can be surely penetrated into the micropores of the Y low-concentration sintered layer. Thus, Y ₂ O ₃ can be the containing SiC sintered body and dense silicon carbide layer to obtain a peeling difficult for a plasma processing apparatus electrode plate.

Here, in the method for producing an electrode plate for a plasma processing apparatus of the present invention, it is preferable that the porosity of the Y low-concentration sintered layer is in the range of 3% or more and 10% or less.
In this case, Y in the low density sinter layers, since microporous by deficiency of Y ₂ O ₃ is formed a number, Y ₂ O ₃ and containing SiC sintered body and dense silicon carbide layer more reliably It can be made difficult to peel off.

According to the present invention, it is possible to provide an electrode plate for a plasma processing apparatus in which the SiC sintered body and the dense silicon carbide layer are not easily peeled off, and a method for manufacturing the same.

It is a schematic explanatory view of the electrode plate for a plasma processing apparatus which concerns on this embodiment, (a) is a perspective view, and (b) is a sectional view taken along line bb of (a). Is an enlarged sectional view of a Y ₂ O ₃ containing SiC sintered body used in the plasma processing apparatus electrode plate according to the present embodiment. It is an enlarged cross-sectional view explaining the state which formed the dense silicon carbide layer in the Y ₂ O _{3 containing SiC sintered body of FIG.} It is a flow chart which shows the manufacturing method of the electrode plate for a plasma processing apparatus which concerns on this embodiment.

Hereinafter, the electrode plate for the plasma processing apparatus and the method for manufacturing the electrode plate for the plasma processing apparatus according to the embodiment of the present invention will be described with reference to the attached drawings.
The electrode plate for a plasma processing apparatus according to the present embodiment is, for example, an upper electrode of a pair of electrodes provided in a vacuum chamber of a plasma processing apparatus such as a plasma etching apparatus or a plasma CVD apparatus used in a semiconductor device manufacturing process. It is used as.

1A and 1B are schematic explanatory views of an electrode plate for a plasma processing apparatus according to the present embodiment, FIG. 1A is a perspective view, and FIG. 1B is a sectional view taken along line bb of FIG. 1A. Figure 2 is an enlarged sectional view of a Y ₂ O ₃ containing SiC sintered body used in the plasma processing apparatus electrode plate according to the present embodiment. Figure 3 is an enlarged sectional view illustrating a state of forming a dense silicon carbide layer in Y ₂ O ₃ containing SiC sintered body of FIG.

In FIG. 1, the electrode plate 10 for a plasma processing apparatus has a disk shape, and a plurality of ventilation holes 11 through which a gas for plasma generation is passed are formed. The plasma processing apparatus electrode plate 10, a _Y 2 _{O 3} containing SiC sintered body 12 and a _Y 2 _{O 3} and SiC as an electrode _substrate, at least one surface of the Y 2 _{O 3} containing SiC sintered body 12 It has a dense silicon carbide layer 16 provided.

In the electrode plate 10 for a plasma processing apparatus of the present embodiment, the ventilation holes 11 preferably have a diameter in the range of 0.1 mm or more and 1.0 mm or less. Y ₂ O ₃ aspect ratio of the vent holes 11 in the containing SiC sintered body 12 _(the diameter of Y 2 _{O 3} content thickness / vent hole 11 of the SiC sintered body 12) is preferably 3 or more. When the aspect ratio of the ventilation holes 11 is 3 or more, it becomes difficult for the plasma to reach the back surface of the electrode plate 10 for the plasma processing device, and the wear of the members arranged on the back surface of the electrode plate 10 for the plasma processing device is suppressed. Can be done. Further, in order to prevent the backflow of the gas for plasma generation, the aspect ratio of the ventilation holes 11 is preferably 50 or less.

As _{shown in FIG. 2, the Y 2} O _3- containing SiC sintered body 12 has a Y concentration provided on at least one surface of the Y high-concentration sintered base material 13 and the Y high-concentration sintered base material 13. It has a Y low-concentration sintered layer 14 that is lower than the Y high-concentration sintered base material 13.

The Y high-concentration sintered base material 13 has a Y concentration in the range of 0.3% by mass or more and 7% by mass or less. Y usually exists as _{Y 2} O _3. Y ₂ O ₃ acts as a sintering aid and has an effect of densifying the Y high-concentration sintered base material 13 to improve the strength and thermal impact of the Y high-concentration sintered base material 13. If the Y concentration is too low, the Y high-concentration sintered base material 13 is unlikely to become dense, and the strength may decrease. On the other hand, if the Y concentration is too high, the SiC content may be relatively reduced, and the strength and thermal impact of the Y high-concentration sintered base material 13 may be lowered.
From the above, in the present embodiment, the Y concentration of the Y high-concentration sintered base material 13 is set in the range of 0.3% by mass or more and 7% by mass or less. In order to further improve the strength and thermal impact of the Y high-concentration sintered base material 13, the Y concentration is preferably in the range of 0.8% by mass or more and 5% by mass or less, and 0.8% by mass or more. It is particularly preferable that the range is 4% by mass or less.

The thickness of the Y high-concentration sintered base material 13 is preferably in the range of 1 mm or more and 20 mm or less. When the thickness of the Y high-concentration sintered base material 13 is within this range, the strength of the electrode plate 10 for the plasma processing apparatus is strong, warpage and distortion due to plasma are unlikely to occur, and gas for plasma generation is allowed to pass through. Can be done.

The Y low-concentration sintered layer 14 has a lower Y concentration than the Y high-concentration sintered base material 13, and Y ₂ O ₃ is missing. As shown in FIG. 2, micropores 15 are formed in the Y low-concentration sintered layer 14 due to the deficiency of _{Y 2} O _3. As shown in FIG. 3, the bonding force between the Y low-concentration sintered layer 14 and the dense silicon carbide layer 16 is enhanced by the inclusion of the dense silicon carbide layer 16 in the micropores 15 of the Y low-concentration sintered layer 14. The effect is exhibited. In order to surely obtain this effect, in the present embodiment, the ratio of the Y concentration of the Y low concentration sintered layer 14 to the Y high concentration sintered base material 13 (Y low concentration sintered layer / Y high concentration sintered base material). ) Is 0.2 or less. The ratio of the Y concentration of the Y low concentration sintered layer 14 to the Y high concentration sintered base material 13 is preferably 0.01 or more. Further, the micropores 15 preferably have an average diameter in the range of 0.1 μm or more and 20 μm or less.

If the thickness of the Y low-concentration sintered layer 14 becomes too thin, the amount of the dense silicon carbide layer 16 that penetrates into the fine pores 15 decreases, and sufficient improvement in bonding force cannot be obtained, so that the dense silicon carbide layer cannot be obtained. 16 may be easily peeled off. On the other hand, if the thickness of the Y low-concentration sintered layer 14 becomes too thick, it may be easily peeled off at a portion where the dense silicon carbide layer 16 cannot enter.
From the above, in the present embodiment, the thickness of the Y low-concentration sintered layer 14 is set in the range of 1.0 mm or more and 1.9 mm or less. It is preferable that the thickness of the Y low-concentration sintered layer 14 is 1.3 mm or more in order to surely obtain an improvement in the bonding force.

The dense silicon carbide layer 16 is preferably a layer of SiC having a ^{density of 3.20 g / cm 3 or more.} The dense silicon carbide layer 16 is preferably a CVD-SiC layer formed by a chemical vapor deposition method (CVD method). By forming by the CVD method, the dense silicon carbide layer 16 can easily penetrate into the fine holes 15 of the Y low-concentration sintered layer 14. Therefore, the CVD-SiC layer has a high bonding force with the Y low-concentration sintered layer 14.

Next, a method of manufacturing the electrode plate 10 for the plasma processing apparatus of the present embodiment will be described.
Method of manufacturing a plasma processing apparatus for electrode plates 10 of the present embodiment, as shown in FIG. 3, the manufacturing process S01 of Y ₂ O ₃ containing SiC sintered body, and forming step S02 of dense silicon carbide layer, processed The process S03 is provided.

( _{Manufacturing process of Y 2} O ₃ containing SiC sintered body)
In the manufacturing process S01 of the _{Y 2} O _{3 containing SiC sintered body, the raw material powder mixture obtained by mixing the Y 2} O ₃ powder and the SiC powder is sintered to obtain a Y ₂ O ₃ containing SiC sintered body. .. The Y ₂ O _3- containing SiC sintered body is formed on the surface of at least one of the Y high-concentration sintered base material having a Y concentration in the range of 0.3% by mass or more and 7% by mass or less and the Y high-concentration sintered base material. It has a Y low-concentration sintered layer having a Y concentration lower than that of the Y high-concentration sintered base material, and the Y low-concentration sintered layer has a thickness in the range of 1.0 mm or more and 1.9 mm or less. It is a sintered body.

_{The blending ratio of the Y 2} O ₃ powder and the SiC powder in the raw material powder mixture is _{preferably a ratio in which the content of the Y 2} O ₃ powder is in the range of 0.5% by mass or more and 8% by mass or less with respect to the total of them. .. If _{the content of the Y 2} O ₃ powder is too small, it becomes difficult to proceed with the sintering of SiC, and the obtained Y ₂ O ₃ containing SiC sintered body has a high porosity and a low density, so that the strength is high. It may decrease. In addition, the thickness of the Y low-concentration sintered layer 14 may become too thin. On the other hand, _{if the content of the Y 23} powder is too high, the content of SiC is relatively low, so that the obtained Y ₂ O _3- containing SiC sintered body may have low strength and thermal shock resistance. .. In addition, the thickness of the Y low-concentration sintered layer 14 may become too thick.

As the SiC powder, either α-SiC powder or β-SiC powder may be used. The SiC powder preferably has a D50 (median diameter) in the range of 0.1 μm or more and 10 μm or less. The purity of the SiC powder is preferably in the range of 99.9% by mass or more and 99.99% by mass or less. Further, the Y ₂ O ₃ powder preferably has a D50 in the range of 1 μm or more and 10 μm or less. The purity of the Y ₂ O ₃ powder is preferably in the range of 99.9% by mass or more and 99.999% by mass or less.

The SiC powder and Y ₂ O ₃ powder, it is preferable to mix with the mixing apparatus having a pulverizing function. A ball mill device can be used as the mixing device having a crushing function. As the ball of the ball mill device, _{it is preferable to use a Si 3} N ₄ ball, a SiC ball, or a ball made of a material having a hardness higher than that of SiC. As the container of the ball mill device, it is preferable to use a resin container that does not contain a metal component. _{The average particle size of the Y 2} O ₃ powder in the raw material powder mixture after pulverization and mixing is preferably in the range of 0.1 μm or more and 8 μm or less. If it is less than 0.1 μm, Y ₂ O ₃ defects are likely to occur, and the porosity of the Y low-concentration sintered layer may become excessively large. On the contrary, if the Y ₂ O ₃ powder exceeds 8 μm, Y _{Defects of 2} O ₃ are less likely to occur, and the porosity may become excessively small.

As a method for sintering the raw material powder mixture, a hot press method can be used. Specifically, the raw material powder mixture is filled in a mold having a predetermined shape and fired under pressure using a hot press device to prepare a sintered body. The atmosphere inside the hot press device is preferably a reducing atmosphere. The reducing atmosphere can be an atmosphere containing carbonized gas or hydrogen gas. The firing temperature is preferably in the range of 1900 ° C. or higher and 2100 ° C. or lower. The pressure at the time of firing is preferably in the range of 20 MPa or more and 40 MPa or less. The firing time is preferably in the range of 2 hours or more and 6 hours or less. By sintering using raw material powder mixture, the hot press method of appropriately adjusting conditions as described above, the surface portion of the obtained Y ₂ O ₃ containing SiC sintered body (Y low concentration sintered layer) Y ₂ O ₃ deficiency is likely to occur, and micropores are likely to be formed.

(Step of forming a dense silicon carbide layer)
In forming step S02 of dense silicon carbide layer, the chemical on the surface of the _Y 2 _{O 3} of _Y 2 _{O 3} containing SiC sintered body obtained in the manufacturing process S01 containing SiC sintered body Y low density sintered layer vapor deposition to form dense silicon carbide layer by chemical vapor deposition (CVD) to (CVD-SiC layer), obtaining with CVD-SiC layer _Y 2 _{O 3} containing SiC sintered body. The conditions for forming the CVD-SiC layer by the CVD method are not particularly limited, and the formation conditions used when forming the CVD-SiC layer in the production of an electrode plate for a normal plasma processing apparatus can be adopted.

(Step of forming a dense silicon carbide layer)
In processing step S03, with respect to dense with the resultant CVD-SiC layer forming step S02 of the silicon carbide layer _Y 2 _{O 3} containing SiC sintered body, to form a vent hole 11 by performing the drilling. The drilling process is not particularly limited, and for example, drilling or laser processing can be used.

According to the electrode plate 10 for the plasma processing apparatus according to the present embodiment having the above configuration, the _{Y 2} O ₃ containing SiC sintered body 12 containing _{Y 2} O ₃ and SiC is used as the electrode substrate, and Y is used. ₂ O ₃ content SiC sintered body 12, Y high concentration sintered Yuimotozai 13, and a the Y-enriched sintered substrate of at least one Y of is provided on the surface lightly doped sintered layer 14 ing. Y-enriched sintered Yuimotozai 13 is in the range Y concentration below 0.3 wt% or more 7 wt%, because it contains a relatively large amount of Y ₂ O ₃ which acts as a sintering aid, a dense and high strength Become. Further, Y low concentration sintered layer 14, Y concentration is lower than Y-enriched sintered substrate, the fine holes 15 by loss of Y ₂ O ₃ is formed, dense this microporous 15 carbide By incorporating the silicon layer 16, the bonding force between the Y low-concentration sintered layer 14 and the dense silicon carbide layer 16 is increased. The Y low-concentration sintered layer 14 has a thickness in the range of 1.0 mm or more and 1.9 mm or less, and many dense silicon carbide layers 16 can be inserted into the Y low-concentration sintered layer 14. It is possible to make it difficult for the Y ₂ O ₃ containing SiC sintered body 12 and the dense silicon carbide layer 16 to be peeled off.

Further, in the electrode plate 10 for the plasma processing apparatus of the present invention, the ratio of the Y concentration of the Y low concentration sintered layer 14 to the Y high concentration sintered base material 13 is 0.2 or less, and the Y low concentration baking is performed. the sintered layer _14, since the fine holes 15 by loss of Y 2 _{O 3} is formed a _number, and Y 2 _{O 3} containing SiC sintered body 12 and the dense silicon carbide layer 16 is less likely to reliably peel off.

Further, according to the method for producing an electrode plate for a plasma processing apparatus of the present invention, the Y concentration is lower than that of the Y high-concentration sintered base material, and the Y low-concentration firing in which micropores are formed due to the defect of _{Y 2} O _3. Since the CVD-SiC layer is formed on the surface of the layer by the CVD method, the dense silicon carbide layer can be surely penetrated into the micropores of the Y low-concentration sintered layer. Thus, Y ₂ O ₃ can be the containing SiC sintered body and dense silicon carbide layer to obtain a peeling difficult for a plasma processing apparatus electrode plate.

Further, in the method for manufacturing an electrode plate for a plasma processing apparatus of the present invention, the porosity of the Y low-concentration sintered layer is in the range of 3% or more and 10% or less, and the Y low-concentration sintered layer has Y. _{Since a} large number of micropores are formed due to the defect of 2 O _{3 , the Y 2} O ₃ containing SiC sintered body and the dense silicon carbide layer can be more reliably prevented from peeling off.

Although the embodiments of the present invention have been described above, the present invention is not limited to this, and can be appropriately changed without departing from the technical idea of the invention.
For example, in the present embodiment, the electrode plate 10 for the plasma processing device has a disk shape, but the shape of the electrode plate 10 for the plasma processing device is not particularly limited and may be a square plate shape.

The results of the evaluation test conducted to confirm the action and effect of the electrode plate for the plasma processing apparatus according to the present invention will be described below.

[Examples 1 to 4 of the present invention, Comparative Examples 1 to 4]
As raw material powders, beta-SiC powder (purity: 99.9 wt%, average particle size: 0.4 .mu.m) and _Y 2 _{O 3} powder (purity: 99.9 wt%, average particle diameter: 3.5 [mu] m) and the I prepared it.

The SiC powder and the Y ₂ O ₃ powder were weighed so as to have the blending ratios shown in Table 1 below, put into the container of the ball mill device together with the balls, and mixed at the mixing time shown in Table 1 below. A resin container was used as the container of the ball mill device, and a Si ₃ N ₄ ball was used as the ball.

The obtained raw material powder mixture was filled in a graphite mold and then pressure-baked for 4 hours at a temperature of 1950 ° C. and a pressure of 34.3 MPa using a vacuum hot press device to have a diameter of 380 mm and a thickness of 34.3 MPa. is to prepare a _Y 2 _{O 3} containing SiC sintered body 10 mm. At the time of pressure firing, the inside of the mold was made into a reducing atmosphere by the carbonized gas generated from the graphite member. The obtained Y ₂ O ₃ containing SiC sintered body was polished so that the thickness of the Y low concentration sintered layer was 0.8 mm in Comparative Example 3. In other Examples 1 to 4 of the present invention and Comparative Examples 1, 2 and 4, no polishing process was performed.

The obtained Y ₂ O ₃ containing SiC sintered body was evaluated as follows. The results are shown in Table 1 below.

(Thickness of Y low-concentration sintered layer)
The thickness of the Y low-concentration sintered layer was measured using a scanning electron microscope (SEM) and an electron probe microanalyzer (EPMA). The Y ₂ O ₃ containing SiC sintered body was cut using a cutting machine, and the Y concentration was measured by EPMA while observing the obtained cut surface with SEM, and the thickness of the _{Y 2} O _{3 containing SiC sintered body was measured.} The thickness of the region where the ratio of the Y concentration to the Y concentration in the central portion in the longitudinal direction was 0.2 or less was defined as the thickness of the Y low concentration sintered layer. The thickness of the Y low density sintered layer was measured for both sides of the Y ₂ O ₃ containing SiC sintered body, in Table 1, describing the average value.

(Y concentration)
The Y concentration on the surface of the Y ₂ O ₃ containing SiC sintered body was measured by glow discharge mass spectrometry (GD-MS), and this was defined as the Y concentration of the Y low concentration sintered layer.
Next, a _{sample was cut out from the center of the Y 2} O ₃ containing SiC sintered body in the radial and thickness directions, and the Y concentration thereof was measured by GD-MS, which was referred to as the Y concentration of the Y high concentration sintered base material. bottom. In Table 1, the Y concentration ratio is the ratio of the Y concentration of the Y low concentration sintered layer to the Y concentration of the Y high concentration sintered base material (Y low concentration sintered layer / Y high concentration sintered base material). Was also described.

(Porosity)
The porosity of the Y low-concentration sintered layer was determined by cutting out the Y low-concentration sintered layer of _{the Y 2} O _3- containing SiC sintered body based on the thickness of the Y low-concentration sintered layer measured above. Y Measured with an underwater densitometer using a low-concentration sintered layer.
For the porosity of the Y high-concentration sintered base material, a cubic sample having a size of 5 mm in length × 5 mm in width × 5 mm in thickness was cut out from the center in the radial and thickness directions of _{the Y 2} O _{3 containing SiC sintered body.} This cut-out sample was used for measurement with an underwater densitometer.

(Base strength)
A rectangular sample of 40 mm in length × 4 mm in width × 3 mm in thickness is cut out from the center of each sintered body, and JIS R 1601 (room temperature bending strength test method for fine ceramics) is used using the cut out sample. The three-point bending strength was measured based on the method specified in.

(Heat-resistant impact resistance)
Y ₂ O ₃ containing SiC sintered to 100 ℃, 200 ℃, 300 ℃ , 400 ℃, 500 ℃, poured respectively in an electric furnace maintained at respective temperatures of 600 ° C., was heated at that temperature for 30 minutes, sufficient A large amount of water was stored and placed in a water tank kept at room temperature for quenching. The Y ₂ O ₃ containing SiC sintered body after cooling was visually observed, and confirmed that there are no cracks. The maximum heating temperature at which no cracks were confirmed was defined as thermostable impact resistance.

(Peeling of CVD-SiC layer with _Y 2 _{O 3} CVD-SiC layer containing SiC sinter)
A Y ₂ O _3- containing SiC sintered body is used as a base material, and a CVD-SiC layer (3.20 g / cm ³ or more) having a thickness of 2 mm is formed on one side surface thereof using a CVD device to form a CVD-SiC layer. It was prepared with _Y 2 _{O 3} containing SiC sintered body. This with CVD-SiC layer _Y 2 _{O 3} containing SiC sintered body, the vent hole diameter 0.5mm penetrating in the thickness direction, 1000 in 8mm pitch, formed concentrically, a plasma processing apparatus for electrode plates Got

The prepared electrode plate was attached to a RIE (Reactive Ion Etching) plasma etching apparatus. Next, after the inside of the RIE plasma etching apparatus was evacuated, SF ₆ gas was introduced at 50 sccm, and the electrode plate was plasma-irradiated at 300 W for 1 hour. After plasma irradiation, the electrode plate is taken out from the RIE plasma etching apparatus, and the surface thereof is observed with an optical microscope (100 times) at 10 places so that the total observation field area is 12 mm ^2, and the CVD-SiC layer is peeled off. The presence or absence of was confirmed. Table 1 shows the number of confirmed peelings out of 10 locations.

In Comparative Example 1 in which the blending amount of _{Y 2} O _{3 was 0.1% by mass, the Y concentration of the Y high-concentration sintered base material of the Y 2} O _3- containing SiC sintered body was lower than the range of the present invention. Y The thickness of the low-concentration sintered layer could not be measured. _Further, the substrate strength of Y 2 _{O 3} containing SiC sintered body is lowered. It is considered that this is _{because the amount of Y 2} O ₃ blended was too small, so that the SiC sintering did not proceed, and _{the porosity of the entire Y 2} O ₃ containing SiC sintered body became high and the density became low. .. Further, CVD-SiC _Y 2 _{O 3} containing SiC sintered body with layers, peeling of CVD-SiC layer after the plasma irradiation was observed. This, Y ₂ O ₃ containing SiC sintered overall strength is believed to be due to lower.
On the other hand, in Comparative Example 2 in which the blending amount of _{Y 2} O _{3 was 9% by mass, the Y concentration of the Y high-concentration sintered base material of the Y 2} O _3- containing SiC sintered body was higher than the range of the present invention. The thickness of the Y low-concentration sintered layer became thicker than the range of the present invention. In addition, the strength of the base material and the thermal impact resistance were lowered. It is considered that this is because the content of SiC was relatively reduced. Further, CVD-SiC _Y 2 _{O 3} containing SiC sintered body with layers, peeling of CVD-SiC layer after the plasma irradiation was observed. This, Y ₂ O ₃ substrate strength of the whole containing SiC sintered body and the thermal shock resistance is considered to be due to decreased.

In _{Comparative Example 3 in which the thickness of the Y low-concentration sintered layer of the Y 2} O _3- containing SiC sintered body was thinner than the range of the present invention, peeling of the CVD-SiC layer was observed after plasma irradiation. It is considered that this is because the improvement of the bonding force due to the fine pores of the Y low-concentration sintered layer was not sufficiently exhibited.
In _{Comparative Example 4 in which the thickness of the Y low-concentration sintered layer of the Y 2} O _3- containing SiC sintered body was thicker than the range of the present invention, peeling of the CVD-SiC layer was observed after plasma irradiation. It is considered that this is because the Y low-concentration sintered layer became too thick and peeling occurred in the portion where the CVD-SiC layer could not enter. In Comparative Example 4, the thickness of the Y low-concentration sintered layer was increased by shortening the pulverization and mixing time to 8 hours and _{relatively increasing the particle size of the Y 2} O _{3 powder in the raw material powder mixture.} I made it thicker.

_{On the other hand, in the Y 2} O _3- containing SiC sintered body obtained in Examples 1 to 4 of the present invention, the Y concentration of the Y high-concentration sintered base material is in the range of 0.3% by mass or more and 7% by mass or less. The Y low-concentration sintered layer had a thickness in the range of 1.0 mm or more and 1.9 mm or less, and was excellent in substrate strength and thermal shock resistance. Further, in the Y ₂ O ₃ containing SiC sintered body with the CVD-SiC layer in which the CVD-SiC layer was formed on the Y ₂ O ₃ containing SiC sintered body, the CVD-SiC layer was not peeled off after plasma irradiation. ..
Therefore, according to the present invention embodiment, it was confirmed that can provide useful with CVD-SiC layer Y ₂ O ₃ containing SiC sintered body as a plasma processing apparatus for electrode plates.

10 Electrode plate for plasma processing equipment 11 Vent holes 12 Y ₂ O _3- containing SiC sintered body 13 Y High-concentration sintered base material 14 Y Low-concentration sintered layer 15 Fine holes 16 Dense silicon carbide layer

Claims (4)

Plasma treatment with a Y ₂ O ₃ containing SiC sintered body containing Y ₂ O ₃ and SiC and a dense silicon carbide layer provided on at least one surface of the _{Y 2} O _{3 containing SiC sintered body.} It is an electrode plate for equipment
The Y ₂ O _3- containing SiC sintered body includes at least one of the Y high-concentration sintered base material having a Y concentration in the range of 0.3% by mass or more and 7% by mass or less and the Y high-concentration sintered base material. The surface has a Y low-concentration sintered layer having a Y concentration lower than that of the Y high-concentration sintered base material, and the Y low-concentration sintered layer has a thickness of 1.0 mm or more and 1.9 mm or less. Is in the range of
An electrode plate for a plasma processing apparatus, wherein the dense silicon carbide layer is provided on the surface of the Y low-concentration sintered layer side. The electrode plate for a plasma processing apparatus according to claim 1, wherein the ratio of the Y concentration of the Y low-concentration sintered layer to the Y high-concentration sintered base material is 0.2 or less. Plasma treatment with a Y ₂ O ₃ containing SiC sintered body containing Y ₂ O ₃ and SiC and a dense silicon carbide layer provided on at least one surface of the _{Y 2} O _{3 containing SiC sintered body.} It is a method of manufacturing electrode plates for equipment.
The Y concentration provided on at least one surface of the Y high-concentration sintered base material having a Y concentration in the range of 0.3% by mass or more and 7% by mass or less and the Y high-concentration sintered base material is the Y high. and a low Y low concentration sintered layer than the concentration sintered substrate, the Y low density sintered layer is in 1.9mm below the range of 1.0mm thickness _Y 2 _{O 3} containing SiC sintered A method for manufacturing an electrode plate for a plasma processing apparatus, which comprises a step of forming a dense silicon carbide layer on the surface of the Y low-concentration sintered layer of the body by a chemical vapor phase growth method. Y The method for manufacturing an electrode plate for a plasma processing apparatus according to claim 3, wherein the porosity of the low-concentration sintered layer is in the range of 3% or more and 10% or less.

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