JP2016155705A - Corrosion-resistant member, method for producing the same and electrostatic chuck member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide: a corrosion-resistant member capable of strengthening an adsorption power when applying an electric field when used for an electrostatic chuck device; a method for producing the corrosion-resistant member; and an electrostatic chuck device using the corrosion-resistant member.SOLUTION: There is provided a corrosion-resistant member which comprises at least one selected from ReAlO(Re is a rare earth element), a rare earth oxynitride, an aluminum oxynitride and a rare earth aluminum oxynitride. There is provided an electrostatic chuck device 10 which electrostatically adsorbs a planar sample W using a ceramic base material 20 containing a corrosion-resistant member and is fixed on the ceramic base material 20. There is provided a method for producing a corrosion-resistant member which comprises a sintering step of sintering a molded product of a raw material mixture prepared by mixing a plurality of raw material powders of ReAlO(Re is a rare earth element) in a nitrogen atmosphere.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a corrosion-resistant member, a method for producing the corrosion-resistant member, and an electrostatic chuck device using the corrosion-resistant member, and more particularly, a halogen-based corrosive gas such as a fluorine-based corrosive gas and a chlorine-based corrosive gas, and these The present invention relates to a corrosion-resistant member having high corrosion resistance against plasma, a method for producing the corrosion-resistant member, and an electrostatic chuck device using the corrosion-resistant member.

A production line for semiconductor devices such as IC, LSI, VLSI, and the like includes processes using halogen-based corrosive gases such as fluorine-based corrosive gases and chlorine-based corrosive gases, and plasmas thereof. In these processes, processes such as dry etching, plasma etching, and cleaning are performed on the semiconductor wafer fixed by the electrostatic chuck device. For these treatments, fluorine-based gases such as CF ₄ , SF ₆ , HF, NF ₃ , and F ₂ , chlorine-based gases such as Cl ₂ , SiCl ₄ , BCl ₃ , and HCl, and plasmas of those gases are used. Is done. Since these corrosive gases and plasmas are highly corrosive, corrosion of the electrostatic chuck apparatus by these corrosive gases and plasmas is a problem. Therefore, conventionally, YAG added with yttrium aluminum garnet (Y ₃ Al ₅ O ₁₂ , hereinafter abbreviated as YAG) or a rare earth oxide other than yttrium has been used as a corrosion-resistant material used in the electrostatic chuck device. (For example, refer to Patent Documents 1 and 2).

Japanese Patent Laid-Open No. 10-236871 JP-A-11-157916

  The corrosion-resistant members described in Patent Documents 1 and 2 have high corrosion resistance against halogen-based corrosive gases such as fluorine-based corrosive gases and chlorine-based corrosive gases and their plasmas. These corrosion-resistant members are particularly used in electrostatic chuck devices, so that they are not only highly corrosive, but when used in electrostatic chuck devices, it is important that the corrosion-resistant members have a strong adsorption force when an electric field is applied. It is. Accordingly, the present invention provides a corrosion-resistant member capable of increasing the attractive force when an electric field is applied when used in an electrostatic chuck device, a method for manufacturing the corrosion-resistant member, and an electrostatic chuck device using the corrosion-resistant member. The purpose is to provide.

Conventionally, many perovskite compounds have a structure distorted from cubic lattices such as tetragonal, orthorhombic, and trigonal crystals, so that they exhibit ferroelectricity and electrostatic chuck devices to which a strong electric field is applied. It was considered unsuitable for use. However, the present inventors have found that ReAlO ₃ (Re is a rare earth element) is suitable for the use of an electrostatic chuck device despite having an orthorhombic perovskite structure (LaAlO ₃ structure). It was. Furthermore, the present inventors have added at least one selected from the group consisting of rare earth oxynitride, aluminum oxynitride, and rare earth aluminum oxynitride to ReAlO ₃ (Re is a rare earth element), so that The inventors have found that when used in an electric chuck apparatus, the attractive force when an electric field is applied can be further increased, and the present invention has been completed. That is, the present invention is as follows.
[1] A corrosion-resistant member containing ReAlO ₃ (Re is a rare earth element) and at least one selected from the group consisting of rare earth oxynitrides, aluminum oxynitrides, and rare earth aluminum oxynitrides.
[2] The corrosion-resistant member includes a plurality of crystal grains and a grain boundary existing between two adjacent crystal grains, and is selected from the group consisting of rare earth oxynitride, aluminum oxynitride, and rare earth aluminum oxynitride. The corrosion-resistant member according to [1], wherein at least one selected is present at least at a grain boundary.
[3] Re is yttrium (Y), lanthanum (La), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb) [1] or [2], which is at least one selected from the group consisting of dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb) and lutetium (Lu) The corrosion-resistant member as described in 1.
[4] The corrosion-resistant member according to any one of [1] to [3], wherein a relative dielectric constant at a frequency of 40 Hz or less is 45 or more and a loss tangent (tan δ) is 0.1 or less.
[5] The corrosion-resistant member according to any one of [1] to [4], wherein the average grain size of the crystal grains is 2.0 μm or more and 20 μm or less.
[6] An electrostatic chuck device including the corrosion-resistant member according to any one of [1] to [5].
[7] A method for producing a corrosion-resistant member including a firing step of firing a molded body of a raw material mixture prepared by mixing a plurality of raw material powders of ReAlO ₃ (Re is a rare earth element) in a nitrogen atmosphere.

  According to the present invention, when used in an electrostatic chuck device, there is provided a corrosion-resistant member capable of strengthening an attractive force when an electric field is applied, a method for manufacturing the corrosion-resistant member, and an electrostatic chuck device using the corrosion-resistant member. Can be provided.

FIG. 1 is a schematic view showing an example of the electrostatic chuck device of the present invention.

[Corrosion resistant material]
The corrosion-resistant member of the present invention contains ReAlO ₃ and at least one selected from the group consisting of rare earth oxynitride, aluminum oxynitride, and rare earth aluminum oxynitride. Here, Re represents a rare earth element. Thereby, the dielectric constant of the corrosion-resistant member of the present invention is increased. Note that at least one selected from the group consisting of rare earth oxynitride, aluminum oxynitride and rare earth aluminum oxynitride in the corrosion-resistant member of the present invention may be crystalline or amorphous.

Re of ReAlO ₃ in the corrosion resistant member of the present invention is yttrium (Y), lanthanum (La), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd). ), Terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb) and lutetium (Lu). Re, which is preferable from the viewpoint that the relative permittivity and volume resistivity of the corrosion-resistant member are high and the dielectric loss is low, is at least one selected from the group consisting of lanthanum (La), neodymium (Nd) and samarium (Sm). It is.

The corrosion resistant member of the present invention includes a plurality of crystal grains and a grain boundary existing between two adjacent crystal grains, and the rare earth oxynitride, aluminum oxynitride, and rare earth aluminum oxynitride in the corrosion resistant member of the present invention. At least one selected from the group consisting of nitrides is preferably present at least at the grain boundaries. Thereby, the spontaneous polarizability of the grain boundary part can be improved, and the relative dielectric constant of the corrosion-resistant member can be further increased. Further, at least one selected from the group consisting of rare earth oxynitride, aluminum oxynitride and rare earth aluminum oxynitride in the corrosion resistant member of the present invention may be dissolved in ReAlO ₃ in the crystal grains. .

  The corrosion-resistant member of the present invention is a polycrystal, and the average grain size of the crystal grains in the polycrystal is preferably 2.0 μm or more and 20 μm or less, more preferably 2.0 μm or more and 10 μm or less, and further preferably It is 3.0 micrometers or more and 6.0 micrometers or less. When the average grain size of the crystal grains is 2.0 μm or more and 20 μm or less, the corrosion-resistant member can be made dense, and a sufficient amount of grain boundary phase to improve the relative dielectric constant of the corrosion-resistant member is used as the corrosion-resistant member. Can be formed. Moreover, since the propagation of cracks is irregular, the fracture toughness of the corrosion-resistant member is increased. The average grain size of the crystal grains was observed at 10 points of a 100 μm × 70 μm rectangular range on a 1000 times scale using a scanning microscope, and the maximum grain size of each crystal grain within the rectangular range was determined. It is measured by calculating the average value of the maximum grain sizes of the measured crystal grains.

The proportion of ReAlO ₃ in the corrosion-resistant member of the present invention is preferably 25% by mass to 99% by mass, more preferably 50% by mass to 99% by mass, and further preferably 75% by mass to 99% by mass. It is. When the ratio of ReAlO _{3 in} the corrosion-resistant member is 25% by mass or more and 99% by mass or less, the relative dielectric constant of the corrosion-resistant member can be increased.

  The relative dielectric constant of the corrosion-resistant member of the present invention at a frequency of 40 Hz is preferably 45 or more, more preferably 47 or more, and further preferably 48 or more. When the relative dielectric constant of the corrosion-resistant member of the present invention is 45 or more, the adsorption force of the corrosion-resistant member when an electric field is applied can be increased.

  The loss tangent (tan δ) at a frequency of 40 Hz of the corrosion-resistant member of the present invention is preferably 0.1 or less, more preferably 0.05 or less, and still more preferably 0.01 or less. When the loss tangent (tan δ) at a frequency of 40 Hz of the corrosion-resistant member is 0.1 or less, the desorption characteristics of the electrostatic chuck device when the electric field is removed can be improved.

The intrinsic volume resistance value of the corrosion-resistant member of the present invention is preferably 1 × 10 ¹³ Ω · cm or more, more preferably 1 × 10 ¹⁴ Ω · cm or more, and further preferably 1 × 10 ¹⁵ Ω · cm or more. It is. When the electric resistance is 1 × 10 ¹³ Ω · cm or more of the corrosion-resistant member, the desorption characteristic of the electrostatic chuck device when the electric field is removed can be improved.

  The bending strength of the corrosion-resistant member of the present invention is preferably 160 MPa or more, more preferably 180 MPa or more, and further preferably 200 MPa or more. Here, the bending strength is a value measured by a four-point bending test in accordance with JIS R1601. When the corrosion-resistant member has a bending strength of 160 MPa or more, when the corrosion-resistant member is used in an electrostatic chuck device, there is no practical problem regarding strength.

  The relative density in the corrosion-resistant member of the present invention is preferably 98% or more, more preferably 98.5% or more, and further preferably 99% or more. When the relative density of the corrosion-resistant member is 98% or more, the strength of the corrosion-resistant member can be increased, and the relative dielectric constant of the corrosion-resistant member can be increased.

  A 1-inch silicon wafer is adsorbed to the corrosion-resistant member by applying a voltage of 2.0 kV for 60 seconds to the corrosion-resistant member of the present invention having a thickness of 1 mm and a wafer mounting surface temperature of 25 ° C. The adsorption force is preferably 60 torr or more, more preferably 100 torr or more, still more preferably 120 torr or more, and particularly preferably 130 torr or more. When the suction force is 60 torr or more, a substrate such as a silicon wafer can be reliably fixed to the corrosion-resistant member.

  After applying a voltage of 2.0 kV to the corrosion-resistant member of the present invention having a thickness of 1 mm and a temperature of the wafer mounting surface of 25 ° C. for 60 seconds to adsorb the 1-inch silicon wafer to the corrosion-resistant member The residual adsorptive power when application of voltage is stopped is preferably 15 torr or less, more preferably 10 torr or less, still more preferably 8 torr or less, and particularly preferably 6 torr or less. When the residual adsorption force is 15 torr or less, the substrate can be easily detached from the corrosion-resistant member after the processing of the substrate such as a silicon wafer is finished.

[Method of manufacturing corrosion-resistant member]
The manufacturing method of the corrosion-resistant member of the present invention includes the following firing step and heat treatment step.

(Baking process)
In the firing step, a compact of a raw material mixture prepared by mixing a plurality of raw material powders of ReAlO ₃ (Re is a rare earth element) is fired in a nitrogen atmosphere.

A raw material mixture prepared by mixing a plurality of raw material powders of ReAlO ₃ (Re is a rare earth element) is prepared, for example, as follows. The aluminum oxide powder and the rare earth oxide powder are mixed with a solvent to produce a slurry containing the aluminum oxide powder and the rare earth oxide powder. The average particle diameter of the aluminum oxide powder and the rare earth oxide powder is preferably 0.01 μm or more and 1.0 μm or less, more preferably 0.05 μm or more and 0.5 μm or less, and further preferably 0.1 μm or more. It is 0.25 μm or less. When the average particle size of the aluminum oxide powder and the rare earth oxide powder is 0.01 μm or more and 1.0 μm or less, the cost of the powder raw material can be reduced, and a corrosion-resistant member having a high relative density can be obtained. Further, segregation of aluminum and rare earth oxide in the corrosion resistant member can be suppressed. Examples of the aluminum oxide used as a raw material include α-aluminum oxide, β-aluminum oxide, θ-aluminum oxide, and γ-aluminum oxide. In consideration of sinterability, α-aluminum oxide is preferable among these aluminum oxides. The average particle diameter is an average particle diameter of primary particles, and is a volume average particle diameter measured by a laser diffraction / scattering method.

  Examples of the solvent used in preparing the slurry include water, methanol, ethanol, propanol, butanol, toluene, xylene, acetone, methylene chloride, ethyl acetate, dimethylformamide, diethyl ether and the like. A preferred solvent is at least one selected from the group consisting of water, methanol, ethanol, propanol and butanol. Since the aluminum oxide powder and the rare earth oxide powder are mixed using a solvent, the aluminum oxide powder and the rare earth oxide powder can be mixed uniformly.

  When mixing the aluminum oxide powder and rare earth oxide powder and the solvent, a dispersant may be added. The dispersant is not particularly limited as long as it is adsorbed on the surfaces of the aluminum oxide powder and the rare earth oxide powder to increase the dispersion efficiency of the aluminum oxide powder and the rare earth oxide powder in the solvent. However, in order to reduce the content of metal impurities in the corrosion-resistant member as much as possible, it is preferable that the dispersant does not contain metal ions. From the viewpoint of preventing heteroaggregation of different particles, it is preferable to add a dispersant.

  The apparatus used for mixing the aluminum oxide powder and the rare earth oxide powder and the solvent is not particularly limited as long as a slurry containing the aluminum oxide powder and the rare earth oxide powder uniformly can be produced. Equipment used for mixing aluminum oxide powder and rare earth oxide powder and solvent includes, for example, ball mill, bead mill, disper mill, homogenizer, vibration mill, sand grind mill, attritor, ultrasonic disperser, high pressure disperser, etc. Is mentioned. For example, a ball mill using a medium made of aluminum oxide having a diameter of 1 mm or more and 5 mm or less can be used. By using this ball mill, the specific volume resistance value of the corrosion-resistant member can be improved. The smaller the diameter of the media, the higher the efficiency of mixing and dispersing the aluminum oxide powder and the rare earth oxide powder, and the specific volume resistance value of the corrosion-resistant member can be improved. Moreover, when medialess dispersers such as an ultrasonic disperser and a high-pressure disperser are used for mixing aluminum oxide powder and rare earth oxide powder with a solvent, impurities generated from the media can be reduced. For this reason, when producing a corrosion-resistant member for a semiconductor manufacturing apparatus, it is preferable to use a medialess disperser.

  The molded body of the raw material mixture can be produced, for example, as follows. The raw material mixture containing the aluminum powder and the rare earth oxide powder is preferably granular in order to facilitate the forming of the raw material mixture. Therefore, it is preferable that the drying of the slurry is performed by a method of drying the slurry and forming granules. For example, a spray dryer, an air dryer, a fluid layer, or the like is used for drying the slurry. In order to form granules of mixed powder, dispersants such as polyacrylates, antifoaming agents such as polyethylene glycol-based antifoaming agents, lubricants such as stearic acid, binders such as polyvinyl alcohol, plastics such as polyethylene glycol An agent or the like may be added to the slurry. And the molded object is obtained by uniaxially pressing the obtained raw material mixture in a metal mold | die, or isostatic pressing in a rubber mold.

  The firing temperature when firing the molded body of the raw material mixture is preferably 1400 ° C. or higher and 1600 ° C. or lower, more preferably 1420 ° C. or higher and 1500 ° C. or lower, and further preferably 1430 ° C. or higher and 1450 ° C. or lower. When the firing temperature is 1400 ° C. or higher and 1600 ° C. or lower, abnormal grain growth can be suppressed and a dense sintered body can be obtained, and melting of the sintered body can be suppressed. The firing time in the firing is preferably 1 hour or more and 10 hours or less, more preferably 2 hours or more and 6 hours or less, and further preferably 3 hours or more and 5 hours or less. Further, at least one part of at least one of rare earth oxide, aluminum oxide and rare earth aluminate in the sintered body is nitrided to produce at least one of rare earth oxynitride, aluminum oxynitride and rare earth aluminum oxynitride. Therefore, the firing of the raw material mixture is performed in a nitrogen atmosphere.

  The compact may be fired at normal pressure, but pressure firing is more preferable in that a denser sintered body can be obtained. Examples of the pressure firing include hot isostatic pressure (HIP) firing, hot press (HP) uniaxial pressure firing, and ultrahigh pressure press (UHP) multiaxial pressure firing. The pressure applied to the molded body when the molded body is fired by pressure firing is, for example, 10 MPa or more and 40 MPa or less.

  In addition, you may calcine a molded object before baking a molded object. Thereby, it can suppress that at least 1 sort (s) of rare earth oxides and aluminum oxide remain in a sintered compact, without reacting. The calcining temperature when calcining the molded body is preferably 700 ° C. or higher and 1300 ° C. or lower, more preferably 800 ° C. or higher and 1100 ° C. or lower, and further preferably 900 ° C. or higher and 1000 ° C. or lower. The calcination time in the calcination at the calcination temperature is preferably 1 hour or more and 10 hours or less, more preferably 2 hours or more and 8 hours or less, and further preferably 3 hours or more and 5 hours or less.

  Moreover, you may anneal-treat the molded object baked at the baking process. As a result, lattice defects generated when at least one of rare earth oxynitride, aluminum oxynitride, and rare earth aluminum oxynitride occurs in the sintered body can be reduced, loss tangent of the sintered body can be reduced, and It is possible to improve the specific volume resistance value of the bonded body. The annealing temperature is 900 ° C. or higher and 1500 ° C. or lower, preferably 1100 ° C. or higher and 1400 ° C. or lower. The treatment time for the annealing treatment at the annealing treatment temperature is 5 hours or more and 30 hours or less, preferably 10 hours or more and 30 hours or less.

[Electrostatic chuck device]
An example of the electrostatic chuck device of the present invention will be described with reference to FIG. FIG. 1 is a schematic view showing an example of the electrostatic chuck device of the present invention. The electrostatic chuck device 10 which is an example of the electrostatic chuck device of the present invention includes the corrosion-resistant member of the present invention, and is disposed in the thickness direction of the ceramic substrate 20 with respect to the ceramic substrate 20 and the ceramic substrate 20. The support 30 that supports the ceramic substrate 20 and the adhesive layer 40 disposed between the ceramic substrate 20 and the support 30 are included.

  For example, the portion of the ceramic substrate 20 on which the plate-like sample W is placed is composed of the corrosion resistant member of the present invention. The ceramic substrate 20 includes an electrostatic adsorption electrode 21. The electrostatic chucking electrode 21 is connected to the power feeding terminal 22, and a DC voltage is applied to the electrostatic chucking electrode 21 through the power feeding terminal 22. When a DC voltage is applied to the electrostatic adsorption electrode 21, an electrostatic force is generated on the surface of the ceramic substrate 20 on which the plate-like sample W is placed. Thereby, the plate-like sample W is adsorbed to the ceramic substrate 20, and the plate-like sample W is fixed to the ceramic substrate 20.

  The support 30 supports the ceramic substrate 20. The support 30 includes a flow path 31 through which a cooling medium such as water and an organic solvent flows. By passing a cooling medium such as water and an organic solvent through the flow path 31, the plate-like sample W placed on the ceramic substrate 20 can be cooled, and the plate-like sample W is placed on the ceramic substrate 20. The surface can be controlled to a desired temperature. In order to insulate between the power feeding terminal 22 and the support 30, an insulator 32 is provided around the power feeding terminal 22 in the support 30.

  Since the relative dielectric constant of the corrosion-resistant member of the present invention is high, the adsorption force when adsorbing the plate-like sample W to the ceramic substrate 20 can be increased.

  EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by these Examples.

Measurements and evaluations in Examples and Comparative Examples described below were performed as follows.
(1) Relative density of corrosion resistant member The density of the corrosion resistant member obtained in Examples and Comparative Examples was measured by the Archimedes method, and the relative density was calculated by dividing the measured density by the theoretical density obtained by the following formula. .
Unit cell weight (g) = unit cell weight (g) of samarium aluminum oxide crystal phase × mol% of each crystal phase
Unit cell volume ^(cm 3) = the unit cell volume of samarium oxide aluminum crystal phase (cm ³⁾ × mol% of each crystal phase
Theoretical density (g / cm ³ ) = unit cell weight (g) / unit cell volume (cm ³ )
In addition, mol% of each crystal phase% of samarium aluminum oxide was calculated from the charged amount of raw material powder.
(2) Identification of crystal phase of corrosion-resistant member The crystal phase of the corrosion-resistant member obtained in Examples and Comparative Examples was identified by a powder X-ray diffraction method. For powder X-ray diffraction, an X-ray diffractometer (manufactured by PANalytical, X'Pert PRO MPD) was used.
(3) Identification of Grain Boundary Phase of Corrosion Resistant Member Electron diffraction images of grain boundary phases of corrosion resistant members of Examples and Comparative Examples using a transmission electron microscope (manufactured by JEOL Ltd., model number: JEM-2100F) The crystal lattice images were taken, and the grain boundary phases of the corrosion-resistant members of Examples and Comparative Examples were identified by crystal structure analysis.
(4) Relative permittivity and loss tangent (tan δ) of corrosion resistant member
After processing the corrosion-resistant member of Example and Comparative Example to φ60 × 1 mm, the relative dielectric constant and loss tangent (tan δ) of the corrosion-resistant member at 40 MHz were measured using a precision impedance analyzer (manufactured by Agilent, model number: 4294A). Measured.
(5) Intrinsic Volume Resistance Value of Corrosion Resistant Member After processing the corrosion resistant members of Examples and Comparative Examples to φ60 × 1 mm, the intrinsic volume resistance value of the corrosion resistant member is converted into a digital ultra-high resistance / ammeter by the three-terminal method ( (Advantest Co., Ltd., R83040A) was used for conversion from the current value measured at an applied voltage of 500 V and a holding time of 60 seconds.
(6) Adsorption power of the corrosion-resistant member The corrosion-resistant members obtained in Examples and Comparative Examples were processed to a thickness of 1.0 mm, and an adhesive layer in which an electrode was embedded was formed between the processed corrosion-resistant member and alumina ceramics. An electrostatic chuck was produced. The sample mounting surface temperature of the electrostatic chuck was set to 25 ° C., and a voltage of 2.0 kV was applied to the electrodes for 60 seconds to adsorb the 1 inch silicon wafer to the electrostatic chuck in vacuum (<0.5 Pa). . And the adsorption power with respect to a 1-inch silicon wafer was measured. The measurement was performed by peeling using a load cell, and the maximum peeling stress generated at that time was taken as the adsorption force.
(7) Residual adsorption force of the corrosion-resistant member The corrosion-resistant members obtained in Examples and Comparative Examples were processed to a thickness of 1.0 mm, and an adhesive layer in which an electrode was embedded was formed between the processed corrosion-resistant member and alumina ceramics. Thus, an electrostatic chuck was produced. The sample mounting surface temperature of the electrostatic chuck was set to 25 ° C., and a voltage of 2.0 kV was applied to the electrodes for 60 seconds to adsorb the 1 inch silicon wafer to the electrostatic chuck in vacuum (<0.5 Pa). . Thereafter, the application of voltage was stopped, and the residual adsorption force with respect to the 1-inch silicon wafer immediately after the application of voltage was stopped was measured. The measurement was performed by peeling using a load cell, and the maximum peeling stress generated at that time was defined as the residual adsorption force.
(8) Average particle diameter of crystal grains of corrosion-resistant member After mirror-polishing the corrosion-resistant members of Examples and Comparative Examples, thermal etching was performed at 1400 ° C. for 5 hours, and a scanning electron microscope (manufactured by Hitachi, Ltd., model number) : S-4000), 10 regions of a 100 μm × 70 μm rectangular range were observed on a 1000-fold scale, and the maximum diameter of the crystal grains in each rectangular region was measured. And the average value of the maximum diameter of the measured crystal grain was computed, and the average value was made into the average particle diameter of a crystal grain.

Example 1
Aluminum oxide (Al ₂ O ₃ ) powder (manufactured by Daimei Chemical Co., Ltd., model number: TM-5D) having an average primary particle size of 0.1 μm and oxidation having an average primary particle size of 0.1 μm Samarium (Sm ₂ O ₃ ) powder (manufactured by Nippon Yttrium Co., Ltd., model number: N—Sm ₃ CP) was weighed so as to have the composition shown in Table 1. The weighed aluminum oxide powder, samarium oxide powder and water are put into a ball mill containing alumina balls having a diameter of 1 mm, and the aluminum oxide powder and samarium oxide powder are mixed for 16 hours. A slurry was prepared.

  This slurry was dried and granulated by using a spray dryer (manufactured by Nippon Pris Co., Ltd., model number: TR160) to prepare mixed raw material granules. Next, this mixed powder was formed into a predetermined shape. Then, using a hot press machine (manufactured by Fuji Denpa Kogyo Co., Ltd., Model No .: High Multi 5000), the molded body was added at a firing temperature of 1600 ° C., a firing time of 2 hours, a pressure of 20 MPa, and a nitrogen atmosphere. The sintered body of Example 1 was produced by pressure firing. And the annealing process of 1400 degreeC was performed in air | atmosphere for 10 hours, and the corrosion-resistant member of Example 1 was produced.

(Example 2)
Instead of samarium oxide (Sm ₂ O ₃ ) powder, lanthanum oxide (La ₂ O ₃ ) powder having an average primary particle size of 0.1 μm (manufactured by Japan Yttrium Co., Ltd., model number: N-La3CP) was used. Except for the above, the corrosion-resistant member of Example 2 was produced in the same manner as in Example 1.

(Example 3)
A corrosion-resistant member of Example 3 was produced in the same manner as in Example 1 except that the firing temperature was changed from 1600 ° C. to 1400 ° C.

Example 4
In the process of raising the temperature of the molded body to a firing temperature of 1600 ° C., the example was carried out in the same manner as in Example 1 except that the firing atmosphere was evacuated to 600 ° C. and the firing atmosphere was changed to a nitrogen atmosphere from 600 ° C. 4 corrosion-resistant members were produced.

(Comparative Example 1)
A corrosion-resistant member of Comparative Example 1 was produced in the same manner as in Example 1 except that pressure baking was performed in an argon atmosphere instead of pressure baking in a nitrogen atmosphere.

(Comparative Example 2)
A corrosion-resistant member of Comparative Example 2 was produced in the same manner as in Example 1 except that it was pressure-fired in the air instead of being pressure-fired in a nitrogen atmosphere.

(Evaluation results)
Table 1 shows the evaluation results of the corrosion-resistant members obtained in Examples 1 to 4 and Comparative Examples 1 and 2.

By comparing Examples 1 to 4 and Comparative Examples 1 and 2 in Table 1, at least one selected from the group consisting of rare earth oxynitride, aluminum oxynitride and rare earth aluminum oxynitride is used as the grain boundary. It was found that the relative dielectric constant of the corrosion-resistant member can be improved by the presence thereof. Further, by comparing the Examples 1, 3, 4 and Example 2, also in the rare earth element Re is other than samarium ReAlO _3, when Re of ReAlO ₃ is samarium as well as the dielectric constant is high I understood it.

Claims (7)

A corrosion-resistant member containing ReAlO ₃ (Re is a rare earth element) and at least one selected from the group consisting of rare earth oxynitride, aluminum oxynitride, and rare earth aluminum oxynitride. The corrosion-resistant member includes a plurality of crystal grains and a grain boundary existing between two adjacent crystal grains,
The corrosion-resistant member according to claim 1, wherein at least one selected from the group consisting of the rare earth oxynitride, aluminum oxynitride, and rare earth aluminum oxynitride is present at least at the grain boundary.   Re is yttrium (Y), lanthanum (La), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium The corrosion-resistant member according to claim 1 or 2, which is at least one selected from the group consisting of (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu). .   The corrosion-resistant member according to any one of claims 1 to 3, wherein a relative dielectric constant at a frequency of 40 Hz or less is 45 or more, and a loss tangent (tan δ) is 0.1 or less.   The corrosion-resistant member according to any one of claims 1 to 4, wherein an average grain size of the crystal grains is 2.0 µm or more and 20 µm or less.   An electrostatic chuck device including the corrosion-resistant member according to claim 1. A method for producing a corrosion-resistant member, comprising a firing step of firing a molded body of a raw material mixture prepared by mixing a plurality of raw material powders of ReAlO ₃ (Re is a rare earth element) in a nitrogen atmosphere.