JP2002080270A - Corrosion resistant member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that a corrosion resistant material jointed on a surface of a ceramic base material is likely to come off and poor in corrosion resistance. SOLUTION: The corrosion resistant member 1 is made by joining the corrosion resistant material 3 made of a sintered compact, the main ingredient of which is at least one kind between 2a group or 3a group of the periodic system, on a surface of the ceramic base material 2 made of an aluminum oxide sintered compact. The middle layer 4 made of a sintered compact containing the ingredient of the ceramic base material 2 and the ingredient of the corrosion resistant material 3 is provided between the ceramic base material 2 and the corrosion resistant material 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma processing apparatus used for manufacturing a semiconductor device which requires high corrosion resistance to a corrosive gas such as a fluorine-based gas or a chlorine-based gas or its plasma. The present invention relates to a corrosion-resistant member suitable for a jig such as an inner wall material in a device and a support member for supporting a Si substrate.

[0002]

2. Description of the Related Art The use of plasma, such as a dry etching process for semiconductor manufacturing and plasma coating, has been rapidly advancing in recent years. For example, in a semiconductor manufacturing process, a halogen-based corrosive gas such as a fluorine-based gas and a chlorine-based gas is frequently used in a plasma process, particularly for deposition, etching and cleaning, due to its high reactivity.

Further, in order to prevent corrosion due to gas or plasma, a portion of the inner wall of the apparatus, such as the inner wall, which is in contact with the gas or plasma, is conventionally provided with a periodic pattern on the surface of a ceramic substrate made of an aluminum oxide sintered body. A corrosion-resistant member in which a corrosion-resistant material comprising a Group 2a or 3a element compound is joined is used.

[0004] The corrosion-resistant member is generally made of a 2a-based material on the surface of a ceramic substrate made of an aluminum oxide sintered body.
It is formed by depositing a Group IIIa or Group 3a element compound by a thermal spraying or CVD method to a thickness of 20 to 100 μm.

[0005]

However, a conventionally used corrosion-resistant member is a 2a or 3a element of the periodic table of the periodic table by thermal spraying or CVD on the surface of a ceramic substrate made of an aluminum oxide sintered body. When formed by applying a corrosion-resistant material made of a compound, the relative density of the corrosion-resistant material is about 90%, and at most about 95%, and there is a problem that the corrosion resistance is insufficient due to the large number of open pores. Was.

In addition, thermal spraying or CVD is applied to the surface of a ceramic substrate.
Corrosion-resistant materials to be deposited by the method described above have a thickness of 20 to
Since it is as thin as about 100 μm, it is consumed in a short time, and as a result, there is also a problem that it is not used for a long time.

Further, thermal spraying or CVD is performed on the surface of the ceramic substrate.
When a corrosion-resistant material is applied by such methods as above, the ceramic substrate and the corrosion-resistant material have low adhesion due to low adhesion between the ceramic substrate and the corrosion-resistant material. When heat is applied to the base material and the corrosion-resistant material, a thermal stress is generated between the ceramic base material and the corrosion-resistant material due to a difference in thermal expansion coefficient between the ceramic material and the corrosion-resistant material. There is also a problem that the film easily peels off and loses its function as a corrosion-resistant member.

[0008] The present invention has been devised in view of the above-mentioned problems, and an object of the present invention is to provide a ceramic material having a relatively high-density, thick, corrosion-resistant material firmly bonded to the surface of a ceramic base material for long-term use. It is an object of the present invention to provide a corrosion-resistant member that can be manufactured.

[0009]

According to the present invention, there is provided a sintered body mainly containing at least one element of Group 2a or 3a of the Periodic Table on the surface of a ceramic substrate made of an aluminum oxide sintered body. A corrosion-resistant member obtained by bonding a corrosion-resistant material consisting of a ceramic base material and a corrosion-resistant material, wherein an intermediate layer made of a sintered body containing the ceramic base material component and the corrosion-resistant material component is disposed between the ceramic base material and the corrosion-resistant material. It is a feature.

The difference in thermal expansion coefficient between the ceramic base material and the intermediate layer, and between the corrosion-resistant material and the intermediate layer, is 1 ppm / ° C.
It is characterized by the following.

Further, the intermediate layer has at least a two-layer structure of a first intermediate layer in contact with the ceramic base material and a second intermediate layer in contact with the corrosion-resistant material, and the first intermediate layer has a ceramic base material. The second intermediate layer contains 55 to 95% by volume of the corrosion-resistant material component.

Still further, the corrosion-resistant material has a relative density of 98%.
The above is the feature.

Furthermore, the corrosion-resistant material has a thickness of 200 μm.
The above is the feature.

According to the corrosion-resistant member of the present invention, the ceramic base is made of an aluminum oxide-based sintered body and the sintered body mainly contains at least one element of Group 2a or 3a of the periodic table. The corrosion-resistant material is composed of a sintered body containing the ceramic base component and the corrosion-resistant material component, has good bonding properties to both the ceramic base material and the corrosion-resistant material, and has a thermal expansion coefficient between the two. Since the bonding is performed via the layer, the bonding of the corrosion-resistant material to the ceramic substrate is extremely strong. Therefore, even when heat is applied to the corrosion-resistant member during use, the corrosion-resistant material does not peel off from the ceramic substrate, and the corrosion-resistant member can always be used stably.

In particular, if the difference in thermal expansion coefficient between the ceramic substrate and the intermediate layer and between the corrosion-resistant material and the intermediate layer is set to 1 ppm / ° C. or less, the bondability between the ceramic substrate and the corrosion-resistant material of the corrosion-resistant member when heat is applied. Can be further improved, and the corrosion-resistant member can be used more stably.

The intermediate layer has at least a two-layer structure of a first intermediate layer in contact with the ceramic base material and a second intermediate layer in contact with the corrosion-resistant material, and the first intermediate layer contains 55 to 55 ceramic base components. If 95% by volume and 55 to 95% by volume of the corrosion-resistant material component are contained in the second intermediate layer, the ceramic base and the first intermediate layer, the corrosion-resistant material and the second intermediate layer, and the first and second intermediate layers are formed. The bonding strength of the corrosion-resistant material to the ceramic substrate can be made extremely strong, and the corrosion-resistant member can be used more stably.

Further, since the corrosion-resistant material is formed of a sintered body mainly containing at least one element of Group 2a or Group 3a of the periodic table, the relative density of the corrosion-resistant material is 98%.
% Or more, and when the relative density of the corrosion resistant material is 98% or more, the existence of open pores is almost eliminated and the corrosion resistance is extremely excellent.

Further, since the corrosion-resistant material is formed of a sintered body containing at least one element of Group 2a or Group 3a of the periodic table as a main component, the thickness of the corrosion-resistant material is reduced to 20%.
When the thickness of the corrosion-resistant material is 200 μm or more, it takes a long time to consume the corrosion-resistant material, so that it can be used for a long time.

[0019]

Embodiments of the present invention will be described below in detail.

FIG. 1 is a perspective view showing one embodiment of the corrosion-resistant member of the present invention. The corrosion-resistant member 1 is composed of a ceramic base 2 made of an aluminum oxide sintered body, a 2a group or a 2a group of the periodic table. It is composed of a corrosion-resistant material 3 made of a sintered body containing at least one element of Group 3a as a main component, and an intermediate layer 4 sandwiched between the ceramic base material 2 and the corrosion-resistant material 3.

The ceramic substrate 2 is made of an aluminum oxide sintered body, acts as a substrate for imparting strength and toughness to the corrosion-resistant member 1, and is chipped or cracked when attached to a semiconductor manufacturing apparatus or when washed. Is prevented from occurring.

When the three-point bending strength of the ceramic base material 2 is 150 MPa or more and the fracture toughness is 2 MPa · √m or more, the mechanical strength of the corrosion-resistant member 1 is increased and the ceramic base material 2 is attached to a semiconductor manufacturing apparatus or the like. Occurrence of chipping, cracking and the like at times can be effectively prevented. Therefore, the ceramic substrate 2 has a three-point bending strength of 150 MPa.
As described above, the fracture toughness is preferably set to 2 MPa · √m or more.

The ceramic substrate 2 made of the aluminum oxide sintered body has an alumina purity of 95% by weight.
As described above, when the corrosion resistant member 1 is used in a semiconductor manufacturing apparatus or the like, it is possible to effectively prevent impurities from being mixed into the semiconductor element and adversely affecting the characteristics of the semiconductor element. Therefore, it is preferable that the ceramic substrate 2 made of the aluminum oxide sintered body has an alumina purity of 95% by weight or more.

Further, the ceramic substrate 2 has an anticorrosion material 3 joined to the surface thereof via an intermediate layer 4.

The corrosion-resistant material 3 is made of a sintered body containing at least one element of Group 2a or Group 3a of the periodic table as a main component, specifically, YAG (yttrium aluminum garnet), yttria, Sintered bodies such as magnesia and spinel can be suitably used.

The corrosion-resistant material 3 made of a sintered body such as YAG, yttria, magnesia, and spinel is made of SF6, CF
4. Fluorine-based gases such as CHF3, ClF3, NF3, C4F8, and HF; chlorine-based gases such as Cl2, HCl, BCl3, and CCl4; and halogen-based corrosive gases such as bromine-based gases such as Br2, HBr, and BBr3; It has excellent corrosion resistance to plasma of a halogen-based corrosive gas, and can be effectively prevented from being corroded by a wall material or the like of a semiconductor manufacturing device by being used in a semiconductor manufacturing device or the like.

Since the corrosion-resistant material 3 is formed of a sintered body mainly containing at least one element of Group 2a or Group 3a of the periodic table, the relative density of the corrosion-resistant material 3 is 98%.
And the relative density of the corrosion-resistant material 3 is 98%
By doing so, the existence of open pores is almost eliminated, and the corrosion resistance becomes extremely excellent. Therefore, it is preferable to set the relative density of the corrosion-resistant material 3 to 98% or more.

Further, since the corrosion-resistant material 3 is formed of a sintered body containing at least one element of Group 2a or Group 3a of the periodic table as a main component, the thickness of the corrosion-resistant material 3 is reduced to 20%.
It can be formed to a thickness as thick as 0 μm or more.
When the thickness is 200 μm or more, it takes a long time for the corrosion-resistant material 3 to be consumed, so that it can be used for a long time.

Further, the corrosion-resistant material 3 is bonded to the surface of the ceramic substrate 2 via the intermediate layer 4.

The intermediate layer 4 is made of a sintered body containing two components of the ceramic base material and three components of the corrosion-resistant material, and has good bonding properties to both the ceramic base material 2 and the corrosion-resistant material 3. 3 can be bonded very firmly to the ceramic substrate 2.

The intermediate layer 4 made of a sintered body containing the two components of the ceramic base material and the three components of the corrosion-resistant material has a coefficient of thermal expansion that is equal to the coefficient of thermal expansion of the ceramic substrate 2 and the coefficient of thermal expansion of the corrosion-resistant material 3. When the coefficient is between the coefficients, there is no large difference in thermal expansion coefficient between the ceramic substrate 2 and the corrosion-resistant material 3 and the intermediate layer 4. Therefore, even if heat is applied when the corrosion resistant member 1 is used, no large thermal stress is generated between the ceramic substrate 2 and the corrosion resistant material 3 and the intermediate layer 4, and the corrosion resistant material 3 is firmly attached to the ceramic substrate 2. The corrosion resistant member 1 can always be used stably.

In particular, the ceramic substrate 2 and the intermediate layer 4,
The difference in thermal expansion coefficient between the corrosion resistant material 3 and the intermediate layer 4 is 1 ppm, respectively.
If the temperature is set to / ° C. or less, the bonding property between the ceramic base material 2 and the corrosion-resistant material 3 of the corrosion-resistant member 1 during application of heat can be further improved, and the corrosion-resistant member 1 can be used more stably. It becomes possible. Therefore, it is preferable that the thermal expansion coefficient difference between the ceramic substrate 2 and the intermediate layer 4 and between the corrosion-resistant material 3 and the intermediate layer 4 be 1 ppm / ° C. or less.

Further, as shown in FIG. 2, the intermediate layer 4 has at least a two-layer structure of a first intermediate layer 4a in contact with the ceramic substrate 2 and a second intermediate layer 4b in contact with the corrosion-resistant material 3. One intermediate layer 4a contains 55 to 55 ceramic base components.
95% by volume and the second intermediate layer 4b
Preferably contains 55 to 95% by volume of a corrosion-resistant material component.

A first intermediate layer 4a in contact with the ceramic substrate 2 and a second intermediate layer 4b in contact with the corrosion-resistant material 3
When the first intermediate layer 4a contains 55 to 95% by volume of the ceramic base material component and the second intermediate layer 4b contains 55 to 95% by volume of the corrosion-resistant material component, Since the first intermediate layer 4a contains a large amount of a ceramic base component, the first intermediate layer 4a and the ceramic base 2 are firmly joined together, and the second intermediate layer 4b has a corrosion-resistant material component. , The second intermediate layer 4b and the corrosion-resistant material 3 are firmly joined to each other, and the first intermediate layer 4a is
Since the first intermediate layer 4b is formed of the same components as the first intermediate layer 4b,
The corrosion-resistant material 3 can be bonded very firmly through the intermediate layer 4 composed of the second intermediate layer 4a and the second intermediate layer 4b, and the corrosion-resistant material 3 is effectively prevented from peeling off from the ceramic substrate 2. Thus, the corrosion-resistant member 1 can be used stably for a long period of time.

Although the intermediate layer 4 is formed of two layers, the first intermediate layer 4a and the second intermediate layer 4b, the present invention is not limited to such a two-layer structure. Layer 4a
A plurality of intermediate layers may be interposed between the second intermediate layer 4b and the second intermediate layer 4b. In this case, the content of the ceramic base component and the corrosion-resistant material component of the intervening layer is set such that the layer close to the ceramic base material 2 contains a large amount of the ceramic base component and the layer close to the corrosion-resistant material contains a large amount of the corrosion-resistant material component. With consideration, it is possible to firmly join the ceramic substrate 2 and the first intermediate layer 4a, and the corrosion-resistant material 3 and the respective layers forming the second intermediate layer 4b and the intermediate layer 4. For example, when the first intermediate layer 4a is formed by containing 95% by volume of the ceramic base material component and the second intermediate layer 4b is formed by containing 95% by volume of the corrosion-resistant material component, the first intermediate layer 4a and the second intermediate layer 4b are formed. A first intermediate layer 4a between the intermediate layers 4b;
The intermediate layer containing 65% by volume of the ceramic base material component and 35% by volume of the corrosion-resistant material component is on the side in contact with the second intermediate layer 4b, and the ceramic base component is 35% by volume on the side in contact with the second intermediate layer 4b.
By arranging the intermediate layer containing the corrosion-resistant material component at 65% by volume, it is possible to more firmly join the intermediate layers.

Next, a specific method for producing the above-described corrosion-resistant member 1 will be described.

First, raw material powders to be used as the ceramic base material 2, the corrosion resistant material 3, and the intermediate layer 4 are prepared.

(Adjustment of Raw Material for Ceramic Substrate) Silicon oxide as a sintering aid was added to aluminum oxide as a main component,
Paraffin wax, wax emulsion (wax + emulsifier), PVA (polyvinyl alcohol), PEG (polyethylene glycol) in raw material powder containing 0.1 to 10% by weight of magnesium oxide, calcium oxide, etc.
The desired raw material is adjusted by adding and mixing a desired organic binder such as described above and granulating by spray drying.

(Preparation of Corrosion-Resistant Raw Materials) Aluminum oxide powder and yttria powder were mixed at a ratio of
After calcination at 0 to 1600 ° C., these are pulverized to an average particle diameter of 0.6 to 1.2 μm and a BET specific surface area of ^{2 to 5} m ² /
g of YAG powder is produced.

A + B = 1 0.365 ≦ A ≦ 0.385 0.615 ≦ B ≦ 0.635 A: molar amount of yttria B: molar amount of aluminum oxide Next, paraffin wax and PVA were added to the YAG powder.
(Polyvinyl alcohol), wax emulsion (wax + emulsifier), PEG (polyethylene glycol)
The desired raw material is adjusted by adding and mixing a desired organic binder such as described above and granulating by spray drying.

(Adjustment of Raw Material for Intermediate Layer) The raw material for the intermediate layer is prepared by adding and mixing the above-mentioned raw material for the ceramic base material and the raw material for the corrosion-resistant material by a desired volume%.

When the intermediate layer 4 is formed as a single layer, the raw material for the ceramic substrate and the raw material for the corrosion-resistant material are added and mixed by 50% by volume to adjust the raw material for the intermediate layer.
When it is formed of two layers of the intermediate layer 4a and the second intermediate layer 4b, the raw material for the ceramic base material is 55 to 95% by volume and the raw material for the corrosion resistant material is 5 to 45% for the first intermediate layer 4a. The mixture for the intermediate layer is prepared for the second intermediate layer 4b by mixing 55 to 95% by volume of the corrosion-resistant material and 5 to 45% by volume of the ceramic base material.

Next, each of the above-mentioned raw materials is formed into a predetermined shape by, for example, die press molding. The molding by the mold press is performed by first filling the raw material for the ceramic base material in the mold press molding machine and pressing it with a constant pressure,
Forming a ceramic substrate molded body, then filling the intermediate layer raw material on the ceramic substrate molded body and pressing it at a certain pressure to form an intermediate layer molded body on the ceramic substrate molded body Next, the corrosion resistant material is filled on the intermediate layer molded body and pressed at a constant pressure to form a corrosion resistant material molded body on the intermediate layer molded body. A composite molded article comprising a layer molded article and a corrosion resistant molded article is obtained.

Finally, the composite molded body is degreased at 300 to 600 ° C., if necessary, and then calcined at about 1500 to 1750 ° C. in the air atmosphere. Thus, the corrosion-resistant member 1 as a product to which the corrosion-resistant material 3 is joined is completed.

In this case, the thickness of the corrosion-resistant material 3 is
The thickness of the corrosion-resistant material 3 can be increased to 200 μm or more by adjusting the filling amount of the raw material.
When the thickness is 0 μm or more, it takes a long time to consume the corrosion-resistant material, so that it can be used for a long time.

The corrosion-resistant material 3 has a thickness of 200 μm.
m, the corrosion-resistant material 3 is formed on the intermediate layer 4 to a uniform thickness.
Moreover, it is difficult to form the intermediate layer 4 so as to completely cover the surface, and there is a risk that the corrosion resistance of the corrosion-resistant member 1 is deteriorated. If the thickness of the corrosion-resistant material 3 exceeds 30 mm, the organic binder contained in the material for the corrosion-resistant material is completely degreased when the material for the corrosion-resistant material 3 is fired to form the corrosion-resistant material 3 made of a sintered body. And the mechanical strength of the corrosion-resistant material 3 may be reduced. Therefore, the thickness of the corrosion-resistant material 3 is preferably set to 200 μm or more, and more preferably in the range of 200 μm to 30 mm.

The intermediate layer 4 has a thickness of 200 μm.
m or more, it is possible to form an intermediate layer 4 having a uniform thickness over the entire area between the ceramic base material 2 and the corrosion-resistant material 3. It is possible to join very firmly. Therefore, the thickness of the intermediate layer 4 is preferably set to 200 μm or more.

Further, in the above-described method, the corrosion-resistant member 1 was manufactured by adopting a molding method using a mold press. However, the present invention is not limited to this, and molding methods such as cast molding and injection molding may be employed. good.

The corrosion-resistant member 1 is suitably used for an inner wall material (chamber) of a semiconductor manufacturing apparatus, a microwave introduction window, a focus ring, and the like. For example, it is used for an etching apparatus as shown in FIG. A halogen-based corrosive gas is injected thereinto, RF power is applied to an induction coil 9 wound therearound to convert the gas into plasma, and RF power is similarly applied to the lower electrode 7 to generate a bias, thereby generating a focus ring. In step 6, the plasma is collected near the wafer 8 and a desired etching process is performed. Since the plasma generated by this apparatus comes into contact with the chamber 5 and the focus ring 6, these components are particularly susceptible to corrosion. Therefore, the chamber 5 and the focus ring 6 are connected to the corrosion-resistant member 1.
By forming it with, excellent corrosion resistance is provided, and it is possible to prevent chipping, cracking, and the like from occurring at the time of mounting and cleaning.

[0050]

Next, embodiments of the present invention will be described. (Example 1) (Raw material for ceramic substrate) The average particle size is 1 to 1 as a main component.
Silicon oxide (SiO ₂ ), magnesium oxide (MgO), and calcium oxide (CaO) are contained as sintering aids in aluminum oxide having a purity of 5 μm and a purity of 95 to 99% by weight, and polyvinyl alcohol (PV) is used as an organic binder.
A), polyethylene glycol (PEG) and wax emulsion (wax + emulsifier) are added and mixed, and granulated by spray drying to prepare a raw material.

(Corrosion-resistant material) YAG, Yttria (Y2
O3), magnesia (MgO), spinel (MgOAl)
₂ O ₃₎ type cerium oxide as a sintering aid (CeO)
Is added, and PVA, PEG and wax emulsion are added and mixed as an organic binder, and granulated by spray drying to prepare each raw material.

(Raw Material for Intermediate Layer) The raw material for the ceramic substrate and the raw material for the corrosion-resistant material are added and mixed by 50% by volume, respectively, to prepare the raw material.

Next, the raw material for the ceramic base material, the raw material for the intermediate layer, and the raw material for the corrosion-resistant material are sequentially formed by die press molding.
A composite molded body composed of a ceramic substrate molded body, an intermediate layer molded body, and a corrosion resistant molded body each having a diameter of 30 mm and a thickness of 5 mm is obtained.

Next, the composite molded body was degreased at 350 ° C. for 2 hours, and then baked at 1500 to 1750 ° C. for 5 hours, and each of the ceramic base material, the intermediate layer and the corrosion-resistant material were composed of the components shown in Table 1. Samples were made.

Further, as a conventional example, a ceramic substrate (diameter 30 mm, thickness 5 m) made of an aluminum oxide sintered body is used.
m), samples (corresponding to samples Nos. 9 to 12) were formed by spraying a corrosion-resistant material mainly composed of YAG and yttria to a diameter of 30 mm and a thickness of 1 mm, and by CVD.

The relative density of the corrosion-resistant material of each sample was determined by the following equation.

(Sintered Density / Theoretical Density) × 100 = Relative Density (%) Further, the thermal expansion coefficients of the ceramic base material, the intermediate layer, and the corrosion-resistant material of each sample were measured in accordance with JISR1618 (the measurement range was: , Room temperature to 1500 ° C).

Then, in order to evaluate the bonding state of each sample, a heat cycle (room temperature to 1400 ° C.) was repeatedly applied to each sample, and the corrosion-resistant material was separated from the ceramic base material when the number of heat cycles was less than 20 times. Things are XX, 20
The sample that was peeled off after less than 30 times was evaluated as x, and the sample that was not peeled even after 60 times was evaluated as ◎.

Next, in order to evaluate the corrosion resistance of each sample, the corrosion-resistant material of each sample was mirror-finished by lapping and RIE (Reactive Ion Etchin).
g) Set in an apparatus and exposed to plasma in a Cl ₂ gas atmosphere for 3 hours.
The etching rate per minute was calculated and evaluated.

The numerical value of the etching rate is a purity of 9
An aluminum oxide sintered body of 9.9% by weight was used as a reference sample, and evaluation was made by relative comparison when the etching rate was set to 1. The evaluation criteria were x for an etching rate of 0.8 or more, ○ for an etching rate of 0.5 or less, and ◎ for an etching rate of 0.3 or less.

Table 1 shows the evaluation results.

[0062]

[Table 1]

As is clear from Table 1, the product of the present invention (Sample No. 1) provided with an intermediate layer between the ceramic substrate and the corrosion-resistant material.
In the case of 1 to 8), since the bonding with the ceramic substrate and the corrosion-resistant material is extremely strong, even if the heat cycle is repeatedly applied, the corrosion-resistant material does not peel off from the ceramic substrate,
It can be used for a long time.

On the other hand, a conventional example in which a corrosion-resistant material is applied to a ceramic substrate by thermal spraying or CVD (samples Nos. 9 to 12)
It can be seen that when the number of application of the heat cycle is less than 30 times, the corrosion resistant material peels off from the ceramic substrate and cannot be used for a long time.

The products of the present invention (Sample Nos. 1 to 8)
Since the relative density of the corrosion-resistant material is 98% or more and the etching rate is 0.5 (Å / min) or less, which is extremely excellent in corrosion resistance, the corrosion-resistant material is less consumed and can be used for a long time. .

On the other hand, the conventional product (sample Nos. 9 to 1)
In the case of 2), when the etching rate is 0.81 (以上 / min) or more, the corrosion resistance is poor and is consumed in a short time.

Example 2 (Raw material for ceramic base material)
Silicon oxide (SiO ₂ ), magnesium oxide (MgO), and calcium oxide (CaO) are contained as sintering aids in aluminum oxide having a purity of 5 μm and a purity of 95 to 99% by weight, and polyvinyl alcohol (PV) is used as an organic binder.
A), polyethylene glycol (PEG) and a wax emulsion are added and mixed, and granulated by spray drying to prepare raw materials.

(Raw material for corrosion resistant material) YAG (yttrium aluminum garnet), yttria (Y2O3),
Cerium oxide (CeO) is added as a sintering aid to one kind of spinel (MgOAl ₂ O ₃ ), PVA, PEG and wax emulsion are added and mixed as an organic binder, and granulated by spray drying to prepare each raw material. .

(Raw Material for Intermediate Layer) The raw material for the intermediate layer for forming the first and second intermediate layers by adding and mixing the above-mentioned raw material for the ceramic substrate and the raw material for the corrosion-resistant material in the ratio shown in Table 2. To adjust.

Next, a raw material for a ceramic base material, a raw material for an intermediate layer, and a raw material for a corrosion-resistant material are sequentially formed by die press molding.
A composite molded body composed of a ceramic substrate molded body, an intermediate layer molded body, and a corrosion resistant molded body each having a diameter of 30 mm and a thickness of 2 mm is obtained.

Next, the composite molded body was degreased at 350 ° C. for 2 hours, and then baked at 1500 to 1750 ° C. for 5 hours, and each of the ceramic base material, the intermediate layer, and the corrosion-resistant material was composed of the components shown in Table 2 Samples were made.

The relative density of the corrosion-resistant material of each sample was determined by the following equation.

(Sintered Density / Theoretical Density) × 100 = Relative Density (%) Further, the thermal expansion coefficients of the ceramic base material, the intermediate layer, and the corrosion-resistant material of each sample were measured in accordance with JISR1618 (the measurement range was: , Room temperature to 1500 ° C).

Then, in order to evaluate the bonding state of each sample, a heat cycle (room temperature to 1400 ° C.) was repeatedly applied to each sample, and the corrosion-resistant material was separated from the ceramic base material when the number of heat cycles was less than 20 times. Things are XX, 20
The sample that was peeled off after less than 30 times was rated as X, the one that was peeled off after less than 60 to 90 times was rated as ○, and the one that was not peeled even after 90 times was rated as ◎.

Next, in order to evaluate the corrosion resistance of each sample, the corrosion-resistant material of each sample was mirror-finished by lapping, and RIE (Reactive Ion Etchin).
g) Set in an apparatus and exposed to plasma in a Cl ₂ gas atmosphere for 3 hours.
The etching rate per minute was calculated.

The numerical value of the etching rate is 9
A value obtained by relative comparison when an etching rate of 1 was set to 9.9% by weight of an aluminum oxide sintered body as a reference sample.

Table 2 shows the evaluation results.

[0078]

[Table 2]

As is clear from Table 2, the first intermediate layer containing 55 to 95% by volume of the ceramic base component between the ceramic base and the corrosion-resistant material, and the first intermediate layer containing 55 to 95% by volume of the corrosion-resistant material component A second intermediate layer (Sample No. 24,
25, 27, 30 to 36, 39, and 40), the ceramic substrate and the corrosion-resistant material are bonded extremely firmly, and the corrosion-resistant material peels off from the ceramic substrate even when a heat cycle is repeatedly applied. It can be used for a long time without any problem.

[0080]

According to the corrosion-resistant member of the present invention, a ceramic base made of an aluminum oxide-based sintered body and a sintered body mainly containing at least one element of Group 2a or 3a of the periodic table are provided. A corrosion-resistant material consisting of a sintered body containing the ceramic base material component and the corrosion-resistant material component, has good bonding properties to both the ceramic base material and the corrosion-resistant material, and has a coefficient of thermal expansion between the two. Since the bonding is performed via a certain intermediate layer, the bonding of the corrosion-resistant material to the ceramic substrate is extremely strong. Therefore, even when heat is applied to the corrosion-resistant member during use, the corrosion-resistant material does not peel off from the ceramic substrate, and the corrosion-resistant member can always be used stably.

In particular, if the difference in thermal expansion coefficient between the ceramic substrate and the intermediate layer and between the corrosion-resistant material and the intermediate layer is set to 1 ppm / ° C. or less, the bonding property between the ceramic substrate and the corrosion-resistant material of the corrosion-resistant member when heat is applied. Can be further improved, and the corrosion-resistant member can be used more stably.

Further, the intermediate layer has at least a two-layer structure of a first intermediate layer in contact with the ceramic base and a second intermediate layer in contact with the corrosion-resistant material. If the second intermediate layer contains 55 to 95% by volume of the corrosion-resistant material component, the ceramic base material and the first intermediate layer, the corrosion-resistant material and the second intermediate layer, and the first and second The bonding strength between the two intermediate layers can be increased, and thereby the bonding of the corrosion-resistant material to the ceramic base material can be made extremely strong, so that the corrosion-resistant member can be used more stably.

Further, since the corrosion-resistant material is formed of a sintered body mainly containing at least one element of Group 2a or 3a of the periodic table, the relative density of the corrosion-resistant material is 98%.
% Or more, and when the relative density of the corrosion resistant material is 98% or more, the existence of open pores is almost eliminated and the corrosion resistance is extremely excellent.

Furthermore, since the corrosion-resistant material is formed of a sintered body containing at least one element of Group 2a or Group 3a of the periodic table as a main component, the thickness of the corrosion-resistant material is reduced to 20%.
When the thickness of the corrosion-resistant material is 200 μm or more, it takes a long time to consume the corrosion-resistant material, so that it can be used for a long time.

[Brief description of the drawings]

FIG. 1 is a perspective view showing one embodiment of a corrosion resistant member of the present invention.

FIG. 2 is a perspective view showing another embodiment of the corrosion-resistant member of the present invention.

FIG. 3 is a schematic view of the inside of an etching apparatus provided with the corrosion-resistant member of the present invention.

[Explanation of symbols]

 1: Corrosion resistant member 2: Ceramic base 3: Corrosion resistant material 4: Intermediate layer 4a: First intermediate layer 4b: Second intermediate layer 5: Chamber 6: Focus ring 7: Lower electrode 8: Wafer 9: Induction coil

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H05H 1/46 C04B 35 / 10Z // C23C 16/44 H01L 21/302 B F-term (Reference) 4G026 BA02 BA03 BA06 BB02 BB03 BF04 BG05 BG30 BH06 4G030 AA07 AA12 AA36 BA33 GA35 4K030 AA02 FA01 KA46 LA15 5F004 AA16 BA20 BB20 DA04 5F045 BB17 EC05 EM09

Claims (5)

[Claims] An anti-corrosion material comprising a sintered body containing at least one element of Group 2a or 3a of the Periodic Table as a main component is bonded to a surface of a ceramic substrate made of an aluminum oxide sintered body. A corrosion resistant member, wherein an intermediate layer made of a sintered body containing the ceramic base component and the corrosion resistant component is disposed between the ceramic base and the corrosion resistant material. 2. The corrosion-resistant member according to claim 1, wherein the difference in thermal expansion coefficient between the ceramic base material and the intermediate layer, and between the corrosion-resistant material and the intermediate layer, is 1 ppm / ° C. or less. 3. An intermediate layer according to claim 1, wherein said intermediate layer is in contact with a first ceramic substrate.
And at least two of the second intermediate layer in contact with the corrosion-resistant material
The first intermediate layer has a ceramic substrate component of 55 to 95% by volume, and the second intermediate layer has a corrosion resistant component of 55 to 95% by volume. The corrosion-resistant member according to claim 1. 4. The corrosion resistant member according to claim 1, wherein said corrosion resistant material has a relative density of 98% or more. 5. The corrosion resistant member according to claim 1, wherein said corrosion resistant material has a thickness of 200 μm or more.