JP4780932B2 - Corrosion-resistant member, method for manufacturing the same, and member for semiconductor / liquid crystal manufacturing apparatus - Google Patents

Description

The present invention relates to an inner wall material (chamber), a microwave introduction window, a shower head, a corrosion-resistant ring for semiconductor manufacturing equipment (focus ring, shield ring, etc.), etc. for semiconductor / liquid crystal manufacturing equipment that requires high corrosion resistance against corrosive gas or plasma. The corrosion-resistant member is preferably used in which the portion exposed to a corrosive gas containing at least a halogen element or plasma thereof is made of yttrium oxide (Y ₂ O ₃ ).

  In recent years, techniques using plasma have been actively used in various processes such as a dry etching process and a film forming process in semiconductor manufacturing. In the plasma process at the time of manufacturing a semiconductor, a corrosive gas containing a highly reactive fluorine-based or chlorine-based halogen element is often used particularly for etching and cleaning. High corrosion resistance is required for the portions that come into contact with these corrosive gases and plasma.

  The members exposed to these corrosive gases and plasma other than the object to be processed are generally quartz glass, stainless steel, aluminum, ceramics such as alumina sintered bodies and aluminum nitride sintered bodies, and silicon ceramic films on these ceramics. Coated ones were used.

Further, recently, in place of the above-described members, yttrium, aluminum, garnet (hereinafter referred to as YAG) sintered body, Y ₂ O _{3 based} sintered body, or a film thereof is used as a material having excellent corrosion resistance.

Further, the Y ₂ O ₃ sintered body has a small dielectric loss tangent at a high frequency, for example, a microwave band, and therefore can be used as a ceramic for a dielectric resonator.

Patent Document 1 discloses a ceramic component for a semiconductor manufacturing apparatus that is exposed to a corrosive gas containing a halogen element or its plasma, and the ceramic constituting the component is made of a ceramic mainly composed of Y ₂ O ₃ , and conducts heat. The rate is 40 W / m · K or less, and the total emissivity from room temperature to 500 ° C. is 80% or less.

Patent Document 2 discloses a substrate processing member used in an apparatus for processing a substrate with a corrosive gas plasma containing a halogen element, and a portion exposed to the corrosive gas plasma containing a halogen element. An example of a substrate processing member with low metal contamination, characterized by being composed of Y ₂ O ₃ having a relative density of 94% or more and a purity of 99.5% or more is shown.

In Patent Document 3, a portion exposed to corrosive gas containing halogen element or plasma thereof is composed of an oxide containing 30 wt% or more of Y ₂ O ₃ , and the porosity exceeds 3% and is 8% or less. A member is shown that is characterized.

Furthermore, Patent Document 4 shows an example of a plasma-resistant member in which at least a surface region exposed to plasma in a corrosive gas is a Y ₂ O ₃ based sintered body.

Furthermore, in Patent Document 5, the content of a trace amount of metal is, based on weight, Si: 200 ppm or less, Al: 100 ppm or less, and the total amount of Na, K, Ti, Cr, Fe, Ni: 200 ppm or less. An example of a Y ₂ O ₃ sintered body characterized by:

Further, Patent Document 6 discloses that at least a portion exposed to a plasma atmosphere is based on a mass amount of a metal trace component, Si: 400 ppm or less, Al: 200 ppm or less, an average particle size of 200 μm or less, and a porosity of 5 An example of a Y ₂ O ₃ material that is less than or equal to% is shown.

Furthermore, Patent Document 7 discloses that a densified Y ₂ O ₃ sintered body is used in a corrosion-resistant member containing yttria as a main component and using a Y ₂ O ₃ sintered body.

In Patent Document 8, by adding titanium oxide Y ₂ O _3, there is shown an example of Y ₂ O ₃ substrate ceramic composition which enables low temperature sintering.
JP 2001-139365 A JP 2001-179080 A Japanese Patent Laid-Open No. 2001-181024 JP 2002-68838 A JP 2002-255647 A JP 2003-55050 A Japanese Patent Laid-Open No. 2001-181042 JP-A-5-330911

The crystal structures of Y ₂ O ₃ sintered bodies and films used as the various corrosion-resistant members are known to be cubic, hexagonal, monoclinic, and orthorhombic, of which cubic Since the crystal Y ₂ O ₃ is thermally most stable, the members including the Y ₂ O ₃ -based sintered body and film of Patent Documents 1 to 8 are considered to have cubic Y ₂ O ₃ as a main component. It is.

In a member including a sintered body or film of Y ₂ O ₃ quality, when the crystal structure of cubic Y ₂ O ₃ contained therein is ordered, the peak width in X-ray diffraction tends to be reduced, in particular, cubic diffraction intensity of X-ray diffraction peaks of Y ₂ O ₃ is the largest, cubic Y ₂ O ₃ of the half-value width of the best Miller indices representing (222) plane attributed peak of the degree of ordering of the crystal structure By reducing the thickness, it is possible to improve the corrosion resistance against corrosive gas containing halogen element or plasma thereof.

However, a conventional Y ₂ O ₃ sintered body or film made of a corrosion-resistant member is not managed by a method for controlling the crystal structure as described above, and therefore, the cubic Y ₂ O ₃ (222) The full width at half maximum of the plane attribute peak was not controlled to 0.4 ° or less, and there was a case where the full width at half maximum exceeded 0.4 °. For this reason, some crystal structures are not sufficiently ordered, and there are many lattice defects, and this lattice defect has a problem that the corrosion resistance cannot be kept high for a long time.

In the ceramic component for semiconductor manufacturing apparatus of Patent Document 1 and the substrate processing member made of Y ₂ O ₃ of Patent Document 2, the organic binder contained in the molded body is sufficiently degreased in the manufacturing process to reduce the amount of residual carbon. After obtaining a small amount of degreased material, the half width of the X-ray diffraction peak of Y ₂ O ₃ may be increased because the firing is not performed by a firing method that reduces lattice defects, resulting in insufficient crystal structure ordering. There was a problem that the corrosion resistance deteriorated.

Also, members of the Patent Document 3, the lattice defects such as oxygen defects because it does not control the temperature decrease rate during firing is increased, there Re emesis crystal structure is not sufficiently ordered is. In particular, if the temperature lowering rate is too high, oxygen vacancies increase in the obtained member, so that the half-value width of the X-ray diffraction peak becomes large and the crystal structure is insufficiently ordered, resulting in poor corrosion resistance. There was a problem.

Furthermore, the plasma-resistant member of Patent Document 4 describes a production method using a step of granulating Y ₂ O ₃ powder having an average particle size of 0.1 to 5.0 μm and firing it at a temperature of 1500 to 2000 ° C. However, since the temperature drop rate during firing is not controlled, if the temperature drop rate is too fast, the half width of the X-ray diffraction peak of the obtained Y ₂ O ₃ sintered body becomes large, and the crystal structure is sufficiently ordered. There was a problem that the corrosion resistance deteriorated. This problem occurred remarkably when using a Y ₂ O ₃ powder having a small sintering activity in which the average particle size of the powder after granulation exceeded 1 μm. Patent Document 4 describes that the binder contained in the molded body is heated at about 900 ° C. for degreasing. However, when degreasing at about 900 ° C., the holding time is insufficient. Then, the amount of carbon contained in the defatted body increased. When a degreased body with a large amount of carbon is baked to produce a sintered body, the carbon contained in the degreased body reacts with oxygen in the Y ₂ O ₃ crystal lattice and is obtained Y ₂ O ₃ sintered body. Since the number of oxygen defects in the member increases, there is a problem that the half width of the X-ray diffraction peak is further increased, the ordering of the crystal structure is further insufficient, and the corrosion resistance is deteriorated.

The Y ₂ O ₃ sintered body and wafer holding jig of Patent Document 5 and the Y ₂ O ₃ quality member of Patent Document 6 are corrosive by setting the upper limit of the content of metal trace components such as Si and Al. Although we are trying to improve the corrosion resistance against gas and its plasma, if the carbon contained in the organic binder is not removed sufficiently before sintering, or if the temperature drop rate during firing is too fast, the half width of the X-ray diffraction peak will be The crystal structure was not sufficiently ordered and the corrosion resistance was poor.

In the corrosion-resistant member of Patent Document 7, when the organic binder contained in the molded body is degreased at 400 to 600 ° C., if the degreasing temperature is too low or the degreasing time is short, a large amount of carbon remains in the degreased body. In the process of sintering this degreased body, the remaining carbon reacts with oxygen in the Y ₂ O ₃ crystal lattice, resulting in an increase in oxygen defects in the resulting member, resulting in an increase in the half width of the X-ray diffraction peak. However, there has been a problem that the crystal structure is insufficiently ordered and the corrosion resistance is deteriorated. Moreover, when the temperature-falling rate at the time of baking is made high, there existed a problem that ordering of crystal structure became inadequate similarly to the member of patent document 3, for example, and corrosion resistance worsened.

In addition, although the ceramic composition of Patent Document 8 is said to be capable of low-temperature firing by reducing the production cost by adding 0.01 to 20% by weight of titanium oxide, since titanium oxide is added, titanium or not the crystal structure ordering of Y ₂ O ₃ solid solution in the crystal lattice of the Y ₂ O _3, since the compounds containing titanium is or to form a corrosion resistance poor grain boundary phase precipitated in the grain boundary There was a problem of poor corrosion resistance.

  These members in Patent Documents 1 to 8 have a high dielectric loss tangent to electromagnetic waves in a high frequency band, particularly a frequency band (1 to 5 GHz) for generating plasma in a semiconductor manufacturing apparatus, when the crystal structure is not sufficiently regularized. There was also a problem.

In view of the above problems, the present inventors ordered a corrosion resistant member having good corrosion resistance at a portion exposed to a corrosive gas containing at least a halogen element or plasma thereof by ordering the crystal structure of Y ₂ O _3. The present invention has been found out and can be achieved. Also, use Y ₂ O ₃ powder with a large specific surface area and high sintering activity, and to regulate the crystal structure, reduce the carbon content of the defatted body, and further control the temperature-decreasing rate conditions during firing. Thus, it has been found that a method for producing a corrosion-resistant member having good corrosion resistance can be provided.

  The present invention provides a corrosion-resistant member having good corrosion resistance against a corrosive gas containing halogen element or the like and plasma thereof, and also having good corrosion resistance against a corrosive gas containing halogen element or the plasma thereof. It aims at providing the manufacturing method of the corrosion-resistant member which has this.

The corrosion-resistant member of the present invention is a corrosion-resistant member used in a portion exposed to a corrosive gas containing at least a halogen element or plasma thereof, and the Y content is 99.5% by mass or more in terms of Y ₂ O _3. Yes, the carbon content is 100 mass ppm or less, and further contains at least two metal elements including Si and Fe among Si, Fe, Al, Ca, and Mg, and the Si content is in terms of SiO ₂ 300 mass ppm or less, Fe content is 50 mass ppm or less in terms of Fe ₂ O ₃ , Al content is 100 mass ppm or less in terms of Al ₂ O ₃ , and Ca and Mg contents are converted to CaO and MgO, respectively. It consists of a Y ₂ O ₃ sintered body that is 350 mass ppm or less in total, and the half width of the (222) plane attribute peak of cubic Y ₂ O ₃ by X-ray diffraction is 0.21 to 0.2. 6 °, and the difference in average crystal grain size between the vicinity of the surface of the Y ₂ O ₃ sintered body and the deep part (crystals of 0.5 μm or less are excluded from calculation) is 30 μm or less, and the deep part The ratio of the content of the metal element in the vicinity of the surface to the surface is 0.5 to 5.

Further, corrosion-resistant member of the present invention, the lattice distortion of standing-cubic _Y 2 _{O 3} crystals 0. It is characterized by being 2 % or less. Furthermore, wherein the diameter of the crystallites is 5 ~ 1 nm on average.

In addition, corrosion resistant member of the present invention, the Y contained 99.9 wt% in terms _{of Y} 2 _{O 3,} wherein the half width 0. It is 21-0.25 degree, It is characterized by the above-mentioned.

Further, corrosion-resistant member of the present invention has a dielectric loss tangent at 1~5GHz is 1.6 × 10 ^- is characterized in that ⁴ or less.

Furthermore, the corrosion-resistant member of the present invention is characterized in that the porosity is 1 % or less.

The method for producing a corrosion-resistant member according to the present invention includes a powder containing 99.5% by mass or more of Y ₂ O ₃ and a solvent, pulverized until the specific surface area becomes 1 m ² / g or more, and then an organic binder. The slurry is prepared by adding the slurry, and the slurry is spray-dried and granulated, and the content of the metal element in the granulated granule is 300 mass ppm or less in terms of SiO ₂ and Fe is Fe ₂ O _3. 50 mass ppm or less in terms of conversion, Al is 100 mass ppm or less in terms of Al ₂ O ₃ , and Ca and Mg are 350 mass ppm or less in terms of CaO and MgO, respectively. step and the degreasing step of the carbon content to obtain a less brown body 200ppm by degreasing the molded body at a temperature of 300 to 900 ° C., oxygen partial pressure is 0.05 to 1 MPa, oxygen 50 volume% or more In an oxygen atmosphere containing, heated by the following heating rate 15 ° C. / h and left for two hours or more at 1500 to 2000 ° C., firing the degreased body by cooling below the cooling rate 100 ° C. / Time And a firing step .

  In addition, a member for a semiconductor / liquid crystal manufacturing apparatus according to the present invention is made of the corrosion-resistant member.

According to the corrosion-resistant member of the present invention, it is a corrosion-resistant member used in a portion exposed to a corrosive gas containing at least a halogen element or its plasma, and the Y content is 99.5% by mass in terms of Y ₂ O _3. The carbon content is 100 mass ppm or less, and further contains at least two metal elements including Si and Fe among Si, Fe, Al, Ca and Mg, and the Si content is SiO _2. 300 mass ppm or less in terms of conversion, Fe content of 50 mass ppm or less in terms of Fe ₂ O ₃ , Al content of 100 mass ppm or less in terms of Al ₂ O ₃ , and Ca and Mg contents of CaO and MgO, respectively. It consists of a Y ₂ O ₃ sintered body that is 350 mass ppm or less in total, and the half width of the (222) plane attribute peak of cubic Y ₂ O ₃ by X-ray diffraction is 0.21 to 0.21. 0.26 °, and the difference in the average crystal grain size between the vicinity of the surface of the Y ₂ O ₃ sintered body and the deep part (crystals of 0.5 μm or less are excluded from calculation) is 30 μm or less, Since the ratio of the metal element content near the surface to the deep part is 0.5 to 5, the crystal structure is aligned, and the content of the metal element causing the generation of lattice defects is small. Lattice defects that are selectively etched by a corrosive gas containing a halogen element or plasma thereof are reduced, and excellent corrosion resistance can be maintained even when exposed to a corrosive gas for a long period of time. In addition, since the carbon content is 100 ppm by mass or less, carbon is unlikely to exist as free carbon at the grain boundaries, and most of the carbon is solid-solved within the crystal lattice or between the lattices. Therefore, the corrosion resistance of the grain boundary is not deteriorated, and a corrosion resistant member having excellent corrosion resistance can be obtained.

Further, according to the corrosion-resistant member of the present invention, the lattice distortion of the stand-cubic Y ₂ O ₃ crystals 0. By being 2 % or less, since there are few lattice defects, corrosion resistance can be improved. Further, by the diameter of the crystallites is 5 ~ 1 nm on average, it is possible to suppress the reduction in plasma generation efficiency.

Et al is, according to the corrosion-resistant member of the present invention, the content of the Y and Y ₂ O ₃ in terms of 99.9% by mass or more, the half width 0. By setting the angle to 21 to 0.25 °, a corrosion-resistant member having excellent corrosion resistance can be obtained even when exposed to a corrosive gas containing a halogen element or plasma thereof for a long time.

Furthermore, according to the corrosion-resistant member of the present invention, the dielectric loss tangent 1.6 × 10 in 1～5GHz ^- With ⁴ or less, since the electromagnetic energy is less likely to be converted into heat energy in a semiconductor manufacturing device, device This eliminates unnecessary heat generation and reduces plasma energy loss. For this reason, plasma generation efficiency can be increased.

Furthermore, according to the corrosion-resistant member of the present invention, the surface porosity can be reduced by reducing the porosity to 1 % or less, so that the surface area exposed to corrosive gas containing halogen element or plasma thereof is small. Thus, it becomes possible to have better corrosion resistance.

Further, according to the method for producing a corrosion-resistant member of the present invention, a powder containing 99.5% by mass or more of Y ₂ O ₃ and a solvent are put in a mill and pulverized until the specific surface area becomes 1 m ² / g or more. Later, a slurry preparation step of adding an organic binder, spray-drying and granulating the slurry, and the content of metal elements in the granulated granules is that Si is 300 mass ppm or less in terms of SiO ₂ , Fe Is 50 mass ppm or less in terms of Fe ₂ O ₃ , Al is 100 mass ppm or less in terms of Al ₂ O ₃ , and Ca and Mg are 350 mass ppm or less in total in terms of CaO and MgO, respectively. a molding step of manufacturing a body, a degreasing step of the carbon content to obtain a less brown body 200ppm by degreasing the molded body at a temperature of 300 to 900 ° C., oxygen partial pressure is 0.05 to 1 MPa, oxygen In an oxygen atmosphere containing more than 50 vol%, the temperature was raised to the following heating rate 15 ° C. / h and left for two hours or more at 1500 to 2000 ° C., the degreasing by cooling below the cooling rate 100 ° C. / Time By having a firing step for firing the body, a corrosion-resistant member in which ordering of the crystal structure is promoted can be produced. When the raw material ground until the specific surface area becomes 1 m ² / g or more is used, the carbon content of the defatted body is set to 200 ppm, and the temperature lowering rate is set to 100 ° C./hour or less, the sintering activity is increased and the density is small and the specific surface area is small. In addition to producing a sintered body, there are few lattice defects such as oxygen defects, and the half-value width is 0.8. A corrosion-resistant member having excellent corrosion resistance of 21 to 0.26 ° can be manufactured, and since it has excellent corrosion resistance against a corrosive gas containing a halogen element, a corrosive gas containing a halogen element in a semiconductor manufacturing process or Even if exposed to the plasma, it can be used for a long time without thinning or cracking. Moreover, the oxygen partial pressure of the said atmosphere is 0.05-1 Mpa, By containing 50 volume% or more of oxygen, a sintered compact can be densified more.

  In addition, the semiconductor / liquid crystal device member of the present invention is formed from the corrosion-resistant member, so that it has excellent corrosion resistance even when it is exposed to a corrosive gas containing a halogen element or its plasma in the production apparatus, Since the frequency of parts replacement can be reduced, manufacturing costs can be reduced.

Corrosion resistant member of the present invention are those used in the site to be exposed to a corrosive gas and or plasma containing at least halogen element, it is made of Y ₂ O ₃ sintered material.

  As a use of the corrosion-resistant member of the present invention, the first is a member for semiconductor manufacturing equipment (inner wall material, monitoring window, microwave introduction window, microwave coupling antenna, electrostatic chuck, susceptor, etc.), which contains a halogen element. Excellent corrosion resistance against corrosive gas plasma is required. More preferably, the semiconductor manufacturing apparatus member is required to have a low dielectric loss tangent in the microwave band in order to increase the plasma generation efficiency.

The second is an arc tube for a metal vapor discharge lamp that utilizes the translucency of a Y ₂ O ₃ sintered material. An arc tube for a metal vapor discharge lamp that encloses and discharges a halogen gas is required to have corrosion resistance against the halogen gas.

The third is a microwave heating and firing jig having at least a surface thereof made of a Y ₂ O ₃ sintered material. When a corrosive green body such as a compound containing a halogen element is sintered by microwave heating, a firing jig such as a crucible into which the green body is placed is required to have excellent corrosion resistance to the halogen element. A low dielectric loss tangent of the firing jig is preferable because the energy loss of the applied microwave is small, so that the green body can be efficiently sintered with a small amount of electric power. Examples of the corrosive gas containing the halogen element include fluorine-based gases such as SF ₆ , CF ₄ , CHF ₃ , ClF ₃ , NF ₃ , C ₄ F ₈ and HF, Cl ₂ , HCl, BCl ₃ , CCl _{4 and the} like. There are bromine-based gases such as chlorine-based gas, Br ₂ , HBr, and BBr ₃ .

In the case of the first application, when these corrosive gases are irradiated with high-frequency waves such as microwaves, these corrosive gases are turned into plasma, and this plasma comes into contact with each member for a semiconductor manufacturing apparatus. Become. Further, in order to enhance the etching effect performed by dry etching, an inert gas such as Ar may be introduced together with the corrosive gas as described above to generate plasma. The etchable material by corrosive gases, oxide-based materials _{(th-SiO 2, PSG,} BPSG, HTO, P-SiO 2, P-TEOS, SOG or the like), a nitride film-based material (P-SiN, LP -SiN, etc.), silicon-based materials (Si, Poly-Si, a-Si, WSi, MoSi, TiSi, etc.), metal-based materials (Al, Al alloys, TI, TiN, TiW, W, Cu, Pt, Au, etc.) ) When a corrosive fluorine-based gas containing a halogen element reacts with Y ₂ O ₃ , YF ₃ is mainly generated, and when a chlorine-based gas and Y ₂ O ₃ react with each other, YCl ₃ is mainly generated. The melting points (YF ₃ : 1152 ° C., YCl ₃ : 680 ° C.) of these reaction products are the melting points (SiF ₄ ) of reaction products generated by the reaction with quartz and aluminum oxide sintered bodies that have been used conventionally. _{: -90 ℃, SiCl 4: -70} ℃, AlF 3: 1040 ℃, AlCl 3: 178 ℃) above. For this reason, the corrosion-resistant member made of a Y ₂ O ₃ -based sintered body has stable corrosion resistance even when exposed to a corrosive gas containing a halogen element or plasma thereof at a high temperature. In particular, the corrosion-resistant member of the present invention is excellent in corrosion resistance against corrosive gas containing halogen element or plasma thereof because it has few lattice defects and has a regular crystal structure.

Here will be described embodiments of the corrosion resistant member of the present invention.

In the corrosion-resistant member of the present invention, the portion exposed to corrosive gas containing at least a halogen element or plasma thereof has a Y content of 99.5% by mass or more in terms of Y ₂ O ₃ , and a carbon content. It is 100 mass ppm or less, and further contains two or more kinds of metal elements including at least Si and Fe among Si, Fe, Al, Ca, and Mg, and the content of Si is 300 mass ppm or less in terms of SiO ₂ . The content is 50 mass ppm or less in terms of Fe ₂ O ₃ , the Al content is 100 mass ppm or less in terms of Al ₂ O ₃ , and the Ca and Mg contents are 350 mass ppm or less in total in terms of CaO and MgO, respectively. made from one _Y 2 _{O 3} quality sintered body, the half-value width of the (222) plane of the attribution peak cubic _Y 2 _{O 3} by X-ray diffraction is from 0.21 to 0.26 °, the _Y 2 _{O 3} quality With the difference between the average crystal grain size of the near-surface and the deep part of the sintered body (0.5 [mu] m or less of crystal the computation excluded. Hereinafter the same.) Is 30μm or less, the metallic elements of the near-surface for the deep It is specified that the content ratio is 0.5 to 5.

  Thereby, it has the outstanding corrosion resistance with respect to the corrosive gas containing a halogen element, or its plasma. The reason is considered as follows.

If there are lattice defects such as defects of Y and O (oxygen) constituting the crystal lattice of crystals contained in the sintered body of cubic Y ₂ O ₃ material and disorder of Y and O arrangement, It is considered that the plasma of a corrosive gas containing a halogen element selectively etches the atoms of the crystal lattice having the lattice defect because the positioned or adjacent atoms are unstable in terms of electrical and crystal structure. When atoms in a crystal lattice having lattice defects are etched, it becomes difficult to maintain the stability of the adjacent crystal lattice in terms of electrical and crystal structure. Therefore, atoms in the adjacent crystal lattice are subsequently etched. It is considered that this etching occurs in a chain and the etching proceeds. Since the corrosion resistant member of the present invention contains 99.5% by mass or more in terms of Y ₂ O ₃ , cubic Y ₂ O ₃ can be used as the main crystal phase. Further, by setting the half width to 0.4 ° or less , particularly 0.21 to 0.26 °, the crystal structure of the crystal composed of cubic Y ₂ O ₃ constituting the corrosion-resistant member is sufficiently ordered. Therefore, the number of lattice defects is small, and the long-term corrosion resistance against a corrosive gas containing halogen element or plasma thereof can be improved. Further, preferably, the content of Y is in terms _{of Y} 2 _{O 3} 99.9% by mass or more, the half value width is 0.3 ° or less, the crystal structure further by Oh Rukoto particularly .21 to .25 ° Since it is regularized, it can be set as the corrosion-resistant member which was further excellent in corrosion resistance.

On the other hand, if the half width exceeds 0.4 °, the crystal structure of the crystal composed of cubic Y ₂ O ₃ is not sufficiently ordered, so that lattice defects increase and corrosive gas containing halogen element or its Corrosion resistance to plasma is deteriorated.

  In order to obtain a corrosion-resistant member having a half width of 0.4 ° or less in this way, as described in detail later, for example, the specific surface area of the raw material powder of the corrosion-resistant member is increased and included in the degreased body before firing. The production conditions are such that the amount of carbon produced is controlled to be small, and the rate of temperature drop during firing is controlled to reduce lattice defects in the resulting corrosion-resistant member.

Here, in the implementation described above, the cubic _Y 2 of the Miller index of the _{O 3} (222) was chosen plane, (222) plane diffraction of X-ray diffraction peaks of cubic _Y 2 _{O 3} This is because the strength is the highest and the degree of ordering of the crystal structure of cubic Y ₂ O ₃ is best shown. Half width is 0. The fact that Ru 21-0.26 ° der, all crystals constituting the corrosion resistance member is completely crystallized, approaches the lattice constant substantially the same, and the lattice defects little crystal (ideal crystal) Means that .

That is, since the half-value width of the (222) plane attribution peak of the corrosion-resistant member made of an ideal crystal is considered to be smaller than 0.2 °, the half-value width of the corrosion-resistant member of the present invention is the crystallization of each crystal. Although it is larger than the half-value width of the ideal (222) plane attribute peak of the crystal depending on the degree and the lattice constant variation , it is less than about twice the half-value width of the ideal crystal , specifically 0.21. It is estimated that the crystal structure can be ordered by setting the angle to ˜0.26 °, and a corrosion-resistant member having sufficient corrosion resistance can be obtained.

Therefore, in the corrosion-resistant member of the present invention, excellent corrosion resistance to halogen elements and plasma thereof is not more than twice the half-value width of the (222) plane attribute peak of an ideal crystal , specifically 0. .21 to 0.26 ° .

Incidentally, the half-value width of the (222) plane attributed peak of corrosion-resistant member made of the ideal crystal is more precisely is considered to be less than 0.15 °, to allow production to facilitate the production of corrosion-resistant member 0 before Symbol half-width in order. 21 to 0.26 °.

In addition, the half width of the (222) plane attribute peak of cubic Y ₂ O ₃ by X-ray diffraction in the corrosion resistant member of the present invention is measured as follows, for example.

First, the surface portion of the corrosion-resistant member is measured by an X-ray diffraction method using CuKα rays, and the half width of the X-ray diffraction peak attributed to the Miller index (222) plane is measured. The unit of the half width is a diffraction angle of incident X-rays, and is an angle (°) usually expressed by 2θ. The X-ray diffraction pattern of cubic Y ₂ O ₃ is JCPDS (Joint Committee on Powder Diffraction Standards) card no. 41-1105 can be referred to. According to this JCPDS card, the surface spacing of the (222) plane of cubic Y ₂ O ₃ is 3.061 mm, and the diffraction angle 2θ is 29.15 ° when using CuKα rays. Specifically, the results of X-ray diffraction as shown in FIG. 1, the intensity of the peak (P) of 2θ are most peak intensity is large in the vicinity of 29 ° (peak intensity of the tip portion of the peak (P)) P _I Then, a parallel line is drawn in the direction of the horizontal axis 2θ at the peak intensity of P _I / 2, and the distance between two intersections at which the parallel line intersects the peak (P) was obtained as a half width.

Further, the content of Y contained in the corrosion-resistant member can be obtained by quantitative analysis by, for example, ICP emission spectroscopy .

Moreover, the corrosion-resistant member in the above-mentioned embodiment is based on the mass of the metal element, Si is 300 ppm or less in terms of SiO ₂ , Fe is 50 ppm or less in terms of Fe ₂ O ₃ , and Al is 100 ppm in terms of Al ₂ O _3. hereinafter, it shall be the 350ppm or less of Ca and Mg in total and CaO and MgO in terms respectively.

  These metal elements are added intentionally in the manufacturing process, impurities contained in the starting material, water used in the manufacturing process, impurities contained in the binder, metal components such as Fe due to machine wear, etc. When the impurities are mixed into the above-mentioned range, the decrease of the dielectric loss tangent due to the impurities that cause the movement of ions and electrons can be particularly suppressed. Can be further reduced, and can have excellent corrosion resistance with a smaller half-value width.

This is because when Si is mixed into the corrosion-resistant member, Si mainly exists as +4 valent Si ⁴⁺ . The radius of Si ⁴⁺ in the corrosion-resistant member is as small as 1/2 or less than the Y ³⁺ ion radius, and Si ⁴⁺ and Y ³⁺ have different valences, so that Si is contained in the crystal lattice of cubic Y ₂ O _3. Hard to dissolve. For this reason, when it contains a lot of Si, a grain boundary phase containing Si having poor corrosion resistance is generated in a very small amount, and the corrosion resistance cannot be remarkably improved. When the Si content is 300 ppm in terms of SiO ₂ , the grain boundary phase containing Si and having poor corrosion resistance is hardly generated, and therefore the corrosion resistance can be further improved.

When Fe contains more than 50 ppm in terms of Fe ₂ O ₃ , an Fe oxide, for example, an Fe ₂ O ₃ phase is formed at the grain boundary. Since an Fe compound such as Fe ₂ O ₃ is a magnetic substance, it easily reacts electromagnetically with this plasma when exposed to plasma of a gas containing a halogen element. For this reason, the grain boundary phase containing the Fe compound is selectively etched, and the corrosion resistance cannot be remarkably improved. When the Fe content is 50 ppm or less in terms of Fe ₂ O ₃ , a grain boundary phase containing an Fe compound is hardly generated, so that the grain boundary is hardly etched by plasma containing a halogen element, and the corrosion resistance is remarkably improved. .

When the content of Al is more than 100ppm in terms _{of Al} 2 _{O 3,} hexagonal or orthorhombic YAlO _3, there is Re emesis intergranular phase of _Y 4 AlO ₉ monoclinic are formed in trace amounts grain boundaries . These grain boundary phase, there is a Re hyperemesis reduce the corrosion resistance against corrosive gas and or plasma containing a halogen element. When the Al content is 100 ppm or less in terms of Al ₂ O ₃ , since these grain boundary phases are not formed at the grain boundaries, the corrosion resistance can be remarkably improved.

When the Ca and Mg contents exceed 350 ppm in total converted to CaO and MgO, a large amount of oxides of Y and Ca or Mg are generated at the grain boundaries. The crystal phase of the grain boundary phase of this oxide has not been specified. However, if the total content of Ca and Mg exceeds 350 ppm in terms of CaO and MgO , the corrosion resistance does not remarkably improve. It is thought that the amount of product produced affects the quality of corrosion resistance. If the total content of Ca and Mg is 350 ppm or less in terms of CaO and MgO, respectively, the grain boundary phase composed of Y and Ca or Mg oxide can be reduced, so that the corrosion resistance is considered to be particularly improved. To further excellent corrosion resistance member corrosion resistance, it is more preferable that the C a and 100ppm or less.

Further, the corrosion resistance member in the implementation described above, the content of Y and Y ₂ O ₃ in terms of 99.9% by mass or more, or less 0.3 ° the half width by a method with a particular condition and It is preferable to have excellent corrosion resistance even when exposed to a corrosive gas containing a halogen element or plasma thereof for a long time.

Here, even when the Y content is high purity of 99.9% by mass or more in terms of Y ₂ O ₃ , it is necessary to control the production method so that the half width is 0.3 ° or less. Yes, even if the Y content is as high as 99.9% by mass or more in terms of Y ₂ O ₃ , if the half-value width is larger than 0.3 ° because the production method was not controlled, the corrosiveness including halogen elements When exposed to gas or plasma for a long time, it cannot have excellent corrosion resistance. When the Y content is as high as 99.9% by mass or more in terms of Y ₂ O ₃ , the full width at half maximum is 0.3 ° or less, that is, a value that seems to be more accurate than the half width of the ideal crystal described above. Since the crystal structure can be more regular than 0.15 °, the crystal structure becomes more regular, and retains excellent corrosion resistance even when exposed to a corrosive gas containing a halogen element or plasma thereof for a long time. be able to. Most preferably, the corrosion-resistant member has a Y content of 99.95% by mass or more in terms of Y ₂ O ₃ and a half width of 0.25 ° or less.

Furthermore, sites exposed to a corrosive gas or plasma thereof containing a halogen element corrosion resistance member, it is preferable that the thickness of the above 2 mm, sometimes baked corrosion resistance member, a metal element to the surface from the deep corrosion resistant member diffusion Then, since the increase in the concentration of the metal element on the surface is suppressed, the amount of the grain boundary phase containing the metal element on the surface of the corrosion resistant member can be reduced, and the grain boundary phase contains the halogen element. Since it becomes difficult to be corroded by corrosive gas or its plasma, it is further excellent in corrosion resistance. Moreover, since the internal stress in a corrosion-resistant member can be made small, it can be set as a corrosion-resistant member with high mechanical strength. In particular, by setting the thickness to 8 mm or more, it is possible to obtain a corrosion-resistant member having excellent corrosion resistance and particularly high mechanical strength.

Here, the vicinity of the surface and the deep part are defined as follows. When the thickness of the corrosion-resistant member is T, the deep portion is in the range of T / 1.6 to T / 2.4 in the vertical direction from the surface of the corrosion-resistant member. When T is greater than 2 mm, the vicinity of the surface is within 0.4 mm from the surface of the corrosion-resistant member and from the surface, and when T is less than 2 mm, T / 1.6 to T / 2. The inside except the range of 4. Also, if the corrosion resistance member composed of Y ₂ O ₃ quality sintered body has different parts of the wall thickness, the average crystal grain size near the surface and deep measures to select the thicker portion of wall thickness.

Moreover, in the corrosion-resistant member of the present invention, the number of lattice defects that affect the dielectric loss tangent is reduced to a low dielectric loss tangent, and the dielectric loss tangent (tan δ) at 1 to 5 GHz is set to 2 × 10 ⁻³ or less. Since electromagnetic field energy is less likely to be converted into thermal energy, unnecessary heat generation is eliminated in the apparatus, and plasma generation efficiency can be increased.

This is because the smaller the half width of the cubic Y ₂ O ₃ contained in the corrosion resistant member, the smaller the loss of electromagnetic energy propagating in the crystal, and the smaller the dielectric loss tangent. When the corrosion-resistant member is exposed to the plasma of a corrosive gas containing a halogen element, the corrosion-resistant member is usually irradiated with an electromagnetic wave of 1 to 5 GHz. A part of the electromagnetic field energy of the electromagnetic wave changes into heat energy in the corrosion resistant member and generates heat. The larger the amount of generated heat, the greater the loss of electromagnetic field energy for generating plasma. In order to suppress the loss of electromagnetic energy and generate plasma efficiently, it is preferable that the dielectric loss tangent of the corrosion-resistant member is 2 × 10 ⁻³ or less, further 5 × 10 ⁻⁴ or less.

  The dielectric loss tangent is measured by a cavity resonator method or a cylindrical resonator method at a dielectric loss tangent at 1 to 5 GHz.

  Further, according to the corrosion-resistant member of the present invention, the surface porosity exposed to corrosive gas containing halogen element or plasma thereof is reduced because the open pores on the surface can be reduced by setting the porosity to 5% or less. Further, it becomes possible to have better corrosion resistance. The porosity is preferably 2% or less, particularly preferably 1% or less. Moreover, since the open pores on the surface of the corrosion-resistant member have a high probability of being exposed to a corrosive gas containing halogen element or plasma thereof, the open porosity is preferably 5% or less, more preferably 2% among the porosity. Hereinafter, it is particularly preferably 1% or less.

Furthermore, the corrosion-resistant member has a density of 4.8 g / cm ³ or more, thereby reducing the number of open pores on the surface of the corrosion-resistant member, and reducing the surface area exposed to corrosive gas containing halogen element or plasma thereof. It becomes possible to have very good corrosion resistance. When the density is 4.9 g / cm ³ or more, not only the corrosion resistance is improved, but also the dielectric loss can be particularly reduced. The density of the corrosion-resistant member comprising a Y ₂ O ₃ quality sintered body can RiMotomu Mel by the A Rukimedesu method.

Incidentally, the density is the density of a portion including a crystal of cubic Y ₂ O ₃ constituting the corrosion resistant member. That is, the density is the density of the corrosion resistant member _Y 2 _{O 3} quality sintered body.

Further, it is preferable that the lattice distortion of the cubic _Y 2 _{O 3} crystals is below 0.4% or less. Lattice distortion is because there is a Re emesis which can not significantly improve the corrosion resistance increasing number of lattice defects exceeds 0.4%. The average diameter of crystallites (microcrystals that can be regarded as single crystals) of the corrosion-resistant member is preferably 1 to 200 nm. This is because the crystals contained in the corrosion-resistant member of the present invention are composed of a plurality of crystallites. The electromagnetic wave propagating through the crystal is attenuated at the crystallite interface, and the electromagnetic field energy of the attenuated electromagnetic wave is converted into thermal energy. If the crystallite diameter is smaller than 1 nm, the area of the interface between the crystallites increases and the dielectric loss tangent increases. Therefore, a corrosive gas plasma containing a halogen element is generated in the semiconductor manufacturing apparatus, and the plasma is a corrosion-resistant member. If is exposed, its plasma generation efficiency by the dielectric loss of the corrosion-resistant member there is a Re emesis decrease. In addition, if the crystallite diameter exceeds 200 nm, the crystallinity of the crystals constituting the corrosion-resistant member decreases, so that the dielectric loss tangent increases and the plasma generation efficiency may similarly decrease. The crystallite diameter is particularly preferably 5 to 100 nm. Further, since the crystal structure The lattice distortion is reduced is ordered, the half-value width lattice distortion is small tends to decrease.

The crystallite diameter and lattice strain can be measured by, for example, the Hall method . In order to measure the crystallite diameter and lattice distortion of a sample by the Hall method , specifically, an X-ray diffractometer is used, for example, as follows. Correction of X-ray diffraction peak angle is carried out by external standard sample method (SRM640b) with Si. Miller indices of Si used in the method, (111), (220), (311), (400), (331), (422), (511), (440) and (531) plane Ru der. For example crystallite size of the cubic _Y 2 _{O 3,} lattice strain, the Miller index of the cubic _{Y 2 O 3 (211),} (222), (400), (440) and (622) plane X-ray diffraction peaks of using measured by integral breadth method. In this integral width method, the X-ray diffraction peak angle of cubic Y ₂ O ₃ uses a value corrected with reference to the X-ray diffraction peak of Si.
Furthermore, the thermal conductivity is preferably 20 W / m · K or less, and if the thermal conductivity is higher than 20 W / m · K, an attempt is made to increase the input energy to the semiconductor manufacturing apparatus and to increase the plasma density. In this case, the input energy is released as thermal energy to the outside of the system, so that energy loss increases and productivity is not improved. The thermal conductivity can be obtained by measurement based on, for example, JIS R 1611. When calculating thermal conductivity using thermal diffusivity, the value measured by the laser flash method is used for thermal diffusivity.

  Further, in the corrosion resistant member, it is preferable to control the carbon content and the crystal grain size as follows, thereby improving the corrosion resistance and further improving the dielectric loss tangent, mechanical strength, and color unevenness.

  If the carbon content is reduced to 100 ppm or less, carbon is less likely to be present as free carbon, and carbon is liable to be dissolved in the crystal lattice or between lattices, so that the movement of ions and electrons due to the presence of free carbon is suppressed, The dielectric loss tangent can be particularly reduced. In addition, the amount of residual carbon can be calculated | required by the measurement by a carbon analyzer (Horiba EMIA-511 type), for example.

Further, the ratio of the content of the metal element in the vicinity of the surface to the content of the metal element in the deep part is set to 0.5 to 5
And by excellent corrosion resistance, not only a small dielectric loss tangent, to suppress the color unevenness in the appearance, mechanical strength may improvement over to Rukoto. When the concentration of the metal element in the vicinity of the surface and in the deep part is different, the content of the metal element in the vicinity of the surface and in the deep part is different. Furthermore, if the ratio of the metal elements is 0.8 to 3, it can contribute to the suppression of the difference in crystal grain size between the vicinity of the surface and the deep part more effectively. At this time, the difference in crystal grain size between the vicinity of the surface and the deep part is 15 μm or less. When the difference in the average crystal grain size is 30 μm or less, the corrosion-resistant member has a ratio of the content of the metal element in the vicinity of the surface to the content of the metal element in the deep part of 0.5 to 5. Thereby, the difference in the tensor between the vicinity of the surface and the deep part, the difference in the absorption coefficient of the electromagnetic wave in the visible light region, the reflection angle, and the reflectance can be particularly suppressed, so that the mechanical strength is improved and the color unevenness is suppressed. In addition, since metal elements that melt or evaporate in the firing step are not concentrated near the surface, the corrosion resistance can be made uniform from the vicinity of the surface to the deep portion.
The ratio of the metal element can be measured as follows. For example, a laser ablation system (manufactured by LSX-200 CETAC Technologies) is used to irradiate a cross section near the surface and a deep cross section of the Y ₂ O ₃ sintered body with an ICP mass spectrometer (Platform ICP). By analyzing with Micromass), the count number of each element of the metal elements (Si, Fe, Al, Ca, Mg) contained in the vicinity of the surface and in the deep part is obtained, and for each element, the count number in the deep part The ratio of the number of counts near the surface is calculated as the ratio of the content of metal elements.

In order to measure the average crystal grain size, for example, a cross section of a corrosion-resistant member made of a Y ₂ O ₃ sintered material is mirror-polished, and the surface vicinity and the deep part of the obtained mirror surface are each subjected to a metal microscope or a scanning electron The photograph is observed with a microscope (SEM) at a magnification of about 50 to 2000 times. The grain sizes of a plurality of crystals shown in the obtained photograph are measured, and these grain sizes are averaged to obtain an average grain size. When the average crystal grain size is determined by SEM, it is preferable to take a SEM photograph after etching the grain boundary of the mirror-polished sample by heat treatment or chemical treatment. In the measurement of the crystal grain size, crystals having a crystal grain size of 0.5 μm or less are excluded from the calculation of the average crystal grain size because they have a small effect on mechanical strength and color unevenness.

The corrosion resistant member may further contain at least one of Sc and In in an amount of 5 mass% or less in terms of Sc ₂ O ₃ and In ₂ O ₃ in order to further improve the corrosion resistant member by ordering the crystal structure. .

  Next, the manufacturing method of the corrosion-resistant member of this invention is demonstrated.

First, Y ₂ O ₃ Shitsushoyui body as a corrosion-resistant member used in the site to be exposed to corrosive gas or plasma thereof include a halogen _element, a powder containing Y 2 _{O 3} 99.5 wt%, A solvent is put in a mill and pulverized until the specific surface area becomes 1 m ² / g or more, and then an organic binder is added to prepare a slurry . Y ₂ O ₃ by the use of powder you containing 99.5 wt%, may be a composition having a reduced amount of impurities to lower the corrosion resistance. Moreover, the high order Rukoto pulverized to sintering activity until the specific surface area is 1 m 2 ^{/ g} or more, ordered crystal structure to promote the crystallization of cubic Y ₂ O ₃ in the firing step described below Thus, a corrosion-resistant member having the half width of 0.4 ° or less can be manufactured. When the specific surface area is smaller than 1 m ² / g, the crystal structure of the crystals contained in the obtained corrosion-resistant member is not regularized, and the half-value width is larger than 0.4 °.

In particular, the mill for milling, and ion-exchanged water as a solvent, yttrium oxide (Y 2 _{O 3)} after the powder was put a specific surface area by BET was wet milled to more than 1 m 2 ^{/ g,} an organic bond An agent is added to make a slurry. Here, the specific surface area after the wet pulverization was set to 1 m ² / g or more because not only the specific surface area was less than 1 m ² / g, but also the sinterability was poor and the crystal structure was well ordered. This is because the body cannot be obtained.

Further, for example, a ball mill or a vibration mill can be used as a grinding mill used for the slurry preparation. Use high-purity ZrO ₂ balls as the media of the ball mill in order to prevent the media wear product from being mixed into the slurry and thereby prevent the improvement of the ordering of the crystal structure of the sintered body. It is preferable to control the ZrO ₂ content in the obtained sintered body to 0.1% by mass or less.

Furthermore, a bead mill can also be used as the mill for grinding. As the media of the bead mill, it is preferable to use high-purity ZrO ₂ beads as in the ball mill in order to obtain pulverized particles having a smaller particle diameter. Also in this case, it is preferable to control the amount of wear of the ZrO ₂ balls during pulverization and to control the ZrO ₂ content in the finally obtained sintered body to 0.1% by mass or less.

As the organic binder, use of paraffin wax, wax emulsion (wax + emulsifier), PVA (polyvinyl alcohol), PEG (polyethylene glycol), PEO (polyethylene oxide), or the like is effective. Moreover, about the said solvent, not only ion-exchange water but distilled water, an organic solvent, etc. can be used.

Then, the obtained slurry is granulated with a spray granulator such as a spray dryer, and the resulting raw material powder , which is the obtained granule, is molded by isostatic pressing, and then cut into a predetermined shape by cutting. To do.

Here, the content of the metal element contained in the secondary raw material powder granulated by the spray granulator such as the spray-drying of the present invention is as follows: Si is 300 ppm or less in terms of SiO ₂ and Fe is Fe in terms of mass. 50ppm or less ₂ O ₃ in terms of the following 100ppm of Al in terms _{of Al} 2 _{O 3} shall be the 350ppm or less of Ca and Mg in total and CaO and MgO in terms respectively.

Further, among the above metal elements, particularly Al is generally used as a sintering aid, and has an effect of promoting crystal grain growth in the Y ₂ O ₃ sintered body as compared with other elements. is there. Therefore, the content of Al in the secondary raw material powder is preferably reduced, and more preferably Al is 30 ppm or less in terms of Al ₂ O ₃ .

  In addition, the method may be selected according to the shape of the target member. Specifically, a dry molding method such as die press molding or a wet method such as casting molding, extrusion molding, injection molding, or tape molding. Molding by a molding method or the like is also possible.

Then, as the degreasing step, the carbon content by degreasing the molded body containing an organic binder Ru to give the following degreased body 200 ppm. By controlling the carbon content of the defatted body to 200 ppm or less, oxygen defects of crystals contained in the resulting corrosion-resistant member can be reduced, so that the crystal structure is regularized and the half width is controlled to 0.4 ° or less. Can do. When the carbon content exceeds 200 ppm, oxygen contained in the cubic Y ₂ O ₃ crystals reacts with the carbon during the firing of the defatted body and is released out of the system, preventing the ordering of many crystal structures. Oxygen vacancies are generated to the extent that the corrosion resistance is deteriorated, and the half width becomes larger than 0.4 °.

The molded body is degreased at a temperature of 300 to 900 ° C. When the degreasing temperature is less than 300 ° C., a large amount of carbon contained in the molded body remains after firing, and a large amount of remaining carbon exists as free carbon, so that the corrosion resistance of the resulting corrosion-resistant member cannot be significantly improved. If the degreasing temperature exceeds 900 ° C. is liable the carbon solid solution in crystal grains, there is Re emesis that solid solution carbon is to produce a lattice defect, thereby, be significantly ordered crystal structure Therefore, the corrosion resistance cannot be significantly improved.
Thereafter, as a firing step, the degreased body is held at 1500 to 2000 ° C. for 2 hours or more, and then cooled at a temperature lowering rate of 100 ° C./hour or less. Thereby, the crystal structure is ordered, and the corrosion-resistant member having the half width of 0.4 ° or less can be manufactured. When the temperature lowering rate exceeds 100 ° C./hour, lattice defects increase and the crystal structure cannot be sufficiently ordered, so the half width becomes larger than 0.4 °. In addition, it is preferable that the said temperature fall rate is an average temperature fall rate in the 1500-1000 degreeC temperature range. This is because when the average temperature drop rate in this temperature range is controlled to 100 ° C./hour or less, the oxygen defects of the crystals constituting the corrosion-resistant member are efficiently reduced, the variation in the half width is eliminated, and the corrosion resistance is excellent. This is because the yield of the corrosion-resistant member can be improved.

When the firing temperature held in firing is less than 1500 ° C., the corrosion-resistant member made of Y ₂ O ₃ sintered material does not become dense, and when it exceeds 2000 ° C., crystals grow abnormally and the mechanical strength is reduced. It cannot be used as a corrosion-resistant member used in manufacturing equipment. On the other hand, when the rate of temperature decrease is higher than 100 ° C./hour, the number of lattice defects in the resulting corrosion-resistant member increases, so that the corrosion resistance deteriorates. Preferably, the temperature decrease rate is 50 ° C./hour or less. Moreover , it is preferable that the rate of temperature increase during degreasing or after degreasing to the start of holding the firing temperature is 15 ° C./hour or less. Thus, the thermal energy together the uniformly transferred from the surface to deep into the heated, since mutual diffusion of the near-surface from the deep portion of the metal element can be suppressed, the difference in mean crystal grain size near the surface and deep Is 30 μm or less, and a corrosion-resistant member made of a Y ₂ O ₃ sintered material having a ratio of the content of the metal element in the vicinity of the surface to the content of the metal element in the deep part of 0.5 to 5 can be produced. At the same time, whereby, in together when color unevenness particularly suppressed can be manufactured corrosion-resistant member which particularly improves the mechanical strength. Although it depends on the thickness of the corrosion-resistant member and the capacity of the firing furnace, it is more preferably fired at a heating rate of 12 ° C./hour or less in a firing furnace having a capacity of 1 m ³ or more.

Further, when firing in the atmosphere containing oxygen, the partial pressure of oxygen is 0.05 to 1 MPa, and firing is performed in an atmosphere containing 50% by volume or more of oxygen, particularly in an atmosphere containing 80% by volume of oxygen. This is preferable for increasing the density of the sintered body. This is because the oxygen partial pressure in the firing atmosphere is made higher than the oxygen partial pressure in the atmosphere, and firing in an atmosphere containing 50% by volume or more of oxygen makes the sintered body more than firing in the air atmosphere. It can be densified. In general, in order to increase the density of a sintered body, it is necessary to remove the atmospheric gas taken into the pores during the sintering process. In the case of firing in an air atmosphere, the atmospheric gas taken into the closed pores is air (mainly about 21% by volume of oxygen gas and about 78% by volume of nitrogen gas). When the oxygen partial pressure is set higher than the oxygen partial pressure in the atmosphere and the firing is performed in an atmosphere containing 50% by volume or more of oxygen, the oxygen concentration in the gas taken into the closed pores is higher than that in the atmosphere. Get higher. In the sintered body of the present invention, since the diffusion rate of oxygen is faster than that of nitrogen, the higher the oxygen concentration in the gas taken into the closed pores, the more the gas taken into the closed pores moves to the outside of the sintered body. Exclusion can be promoted, which makes it possible to improve the density of the sintered body. To a preferred upper limit of the oxygen partial pressure in the firing atmosphere and 1MPa, when the oxygen partial pressure exceeds 1MPa, residual carbon content of the sintered body after firing there is a Re emesis more than 200 ppm.

Then, a powder containing Y ₂ O ₃ more than 99.5 wt%, after the specific surface area put the solvent in the mill was pulverized until 1 m 2 ^{/ g} or more, and a slurry preparation step of adding an organic binder The slurry is spray-dried and granulated, and the content of metal elements in the granulated granule is 300 mass ppm or less in terms of SiO ₂ , Fe is 50 mass ppm or less in terms of Fe ₂ O ₃ , Al Is 100 mass ppm or less in terms of Al ₂ O ₃ , and Ca and Mg are 350 mass ppm or less in total in terms of CaO and MgO, respectively, and a molding step for producing a molded body using these granules, A degreasing step of degreasing at a temperature of ˜900 ° C. to obtain a degreased body having a carbon content of 200 ppm or less, and in an oxygen atmosphere having an oxygen partial pressure of 0.05 to 1 MPa and containing 50% by volume or more of oxygen. And a firing step of firing the degreased body by raising the temperature at a rate of temperature increase of 15 ° C./hour or less, holding at 1500 to 2000 ° C. for 2 hours or more, and then decreasing the temperature at a rate of temperature decrease of 100 ° C./hour or less. The corrosion resistant member obtained by the manufacturing method has a Y content of Y ₂ O
₃ conversion is 99.5 mass% or more, carbon content is 100 mass ppm or less, and further contains at least two kinds of metal elements including Si and Fe among Si, Fe, Al, Ca, and Mg. , Si content is 300 mass ppm or less in terms of SiO ₂ , Fe content is 50 mass ppm or less in terms of Fe ₂ O ₃ , Al content is 100 mass ppm or less in terms of Al ₂ O ₃ , Ca and Mg The Y ₂ O ₃ sintered body has a total content of 350 mass ppm or less in terms of CaO and MgO, respectively, and the half width of the (222) plane attribute peak of cubic Y ₂ O ₃ by X-ray diffraction is 0.21 to 0.26 °, and the difference in average crystal grain size between the vicinity of the surface and the deep portion of the Y ₂ O ₃ sintered body is 30 μm or less, and the metal element in the vicinity of the surface with respect to the deep portion Contains The ratio becomes corrosion resistant member is 0.5 to 5, and because of its excellent corrosion resistance against corrosive gas or the like containing a halogen element, be exposed to corrosive gas and or plasma containing a halogen element in a semiconductor manufacturing process It can be used for a long time without thinning or cracking, and can be suitably used as a member for a semiconductor manufacturing apparatus and a member for a liquid crystal manufacturing apparatus.

  Furthermore, the corrosion-resistant ring, which is a member for semiconductor manufacturing equipment composed of corrosion-resistant members, has excellent corrosion resistance against corrosive gases containing halogen elements or plasma thereof, and this corrosion-resistant ring requires less frequent component replacement. Therefore, the manufacturing cost can be suppressed.

  Here, FIG. 2 shows an example of an etching apparatus using the corrosion-resistant member of the present invention.

  In FIG. 2, 1 is a chamber, 2 is a clamp ring or focus ring, 3 is a lower electrode, 4 is a wafer, and 5 is an induction coil. In the apparatus of FIG. 2, a corrosive gas containing a halogen element is injected into the chamber 1, and high-frequency power is applied to the induction coil 5 wound around the chamber 1 to turn the gas containing the halogen element into plasma. Further, high frequency power is applied to the lower electrode 3 to generate a bias, and a desired etching process is performed on the wafer 4 fixed by the clamp ring 2. Since the plasma generated in this apparatus comes into contact with the chamber 1 and the clamp ring 2 fixing the wafer 4, these parts are particularly susceptible to corrosion. Therefore, by forming the chamber 1 and the clamp ring 2 with the corrosion-resistant member of the present invention, excellent corrosion resistance can be exhibited, and cracking due to thermal shock can be prevented.

A mill for milling, and ion-exchanged water as a solvent, yttria _{(Y 2 O} 3) shown in Table 1, lanthanoid elements (LN) oxide _{powder, SiO 2, Fe 2 O 3} , Al 2 O 3, CaO, and powders of MgO was put, after the specific surface area was wet ground in a ball mill using ZrO ₂ balls until the values shown in Table 1, PVA (polyvinyl alcohol) 1% by mass as an organic binder, PEG ( 1% by mass of polyethylene glycol) and 1% by mass of PEO (polyethylene oxide) were added to the weight of the powder to prepare a slurry. In addition, the specific surface area dried the slurry before adding an organic binder , and measured the specific surface area of the powder after drying by BET method.

Next , the obtained slurry is spray-dried, dried and granulated, and the obtained granule is molded by isostatic pressing and then cut into a cylindrical shape having an outer diameter of 60 mm and a thickness of 50 mm. A plurality of molded bodies were obtained. The obtained molded body was heated at a temperature rising rate of 100 ° C./hour, held at the temperature shown in Table 1 for 3 hours for degreasing, and degreased until the residual carbon content was 200 ppm or less to obtain a degreased body. The obtained degreased body was heated at an increasing temperature rate shown in Table 1 in an oxygen / nitrogen mixed gas atmosphere having an oxygen partial pressure of 0.062 MPa and a nitrogen partial pressure of 0.04 MPa, and then held at the firing temperature shown in Table 1 for 3 hours. Further, the temperature was lowered at a temperature lowering rate shown in Table 1 and baked.

In this way, we have specimen Nitsu was prepared which was evaluated as follows.

(Half width of (222) plane attribute peak of cubic Y ₂ O ₃ )
Using a Rigaku Co., Ltd. X-ray diffractometer RINT2000 / PC series, the sample surface was analyzed by X-ray diffractometry using CuKα rays, and cubic Y ₂ O lying between 3.04 and 3.09 mm. _{The full} width at half maximum of the (222) plane attribute peak of ₃ was determined. As for the half-width of the sample to which the lanthanoid element oxide was added, the half-width of the diffraction peak having the largest diffraction intensity in the range of the inter-plane spacing of 3.04 to 3.09 mm was determined. Specifically, in FIG. 1, when the intensity of the peak (P) where 2θ is around 29 ° (peak intensity at the tip of the peak (P)) is P _I , the peak intensity is P _I / 2. A parallel line was drawn in the direction of the horizontal axis 2θ, and the distance between two intersections where the parallel line intersected the peak (P) was determined as a half-value width. Note that, in the sample to which the lanthanoid element oxide was added, it was found by measurement by an X-ray diffraction method using a transmission electron microscope that LN was dissolved in cubic Y ₂ O ₃ .

(Carbon content)
The carbon content was measured by a carbon analyzer (EMIA-511 type manufactured by Horiba, Ltd.).

(Content of metal elements (Si, Fe, Al, Ca, Mg))
The contents of Si, Fe, Al, Ca, and Mg are determined by ICP (Inductively Coupled Plasma) emission spectroscopy (ICPS-8100, manufactured by Shimadzu Corporation), and SiO ₂ , Fe ₂ O ₃ , Al ₂ O ₃ , CaO, MgO It converted into content of.

(Difference in average crystal grain size near the surface and a depth portion)
After the sample cross section is mirror-polished, the grain boundary phase is etched, and the size of the crystal grains is measured with a scanning electron microscope (S-800, manufactured by Hitachi, Ltd.). The order of the crystal structure was confirmed by determining the difference between the two. At this time, crystals having a crystal grain size of 0.5 μm or less were excluded from measurement.

(Ratio of metal element content)
By irradiating a laser with a laser ablation system (manufactured by LSX-200 CETAC Technologies) on the cross section near the sample surface and a deep section, and analyzing the evaporated element with an ICP mass spectrometer (manufactured by Platform ICP Micromass) The count number of each metal element (Si, Fe, Al, Ca, Mg) in the vicinity of the surface and in the deep part is obtained as a peak intensity from the spectrum diagram, and the peak of the metal element in the vicinity of the surface with respect to the peak intensity of the deep metal element The intensity ratio was calculated as the ratio of metal element content.

(Dielectric loss tangent tan δ)
The dielectric loss tangent (tan δ) at 2-3 GHz was determined by the cavity resonator method.

(Sintered body density, porosity)
The apparent density and porosity of the sintered body were measured by the Archimedes method using ion-exchanged water.

(Crystallite size, lattice strain only)
Using an X-ray diffractometer, the crystallite diameter and lattice distortion of the sample were measured by the Hall method . Specifically, the Miller index of the cubic _Y 2 _{O 3} (211), as measured by (222), (400), (440) and (622) by using the X-ray diffraction peaks of the surface, the integral width method, in this integration width method, the correction of the X-ray diffraction peak angle of cubic _Y 2 _{O 3,} the external standard sample method using Si by (SRM640b), Si of mirror index (111), (220), (311 ), (400), (331), (422), (511), (440) and (531) Si X-ray diffraction peaks were used as a reference .

(Evaluation of uneven color)
The sample was cut from the center in the axial direction of the cylindrical shape, and the cross section was visually observed to confirm whether color unevenness occurred.

(Etching rate ratio)
The sample surface is mirror-finished, this sample is set in a RIE (Reactive Ion Etching) device, exposed to plasma in a Cl ₂ gas atmosphere for 3 hours, and the etching rate per minute is calculated from the weight loss before and after that. And obtained as a relative comparison value when the etching rate of an alumina sintered body (alumina content 99.8 mass%) prepared as a reference sample is 1, and the relative comparison value is 0.5 or less. It was supposed to be.

  Further, the thermal conductivity was calculated from the thermal diffusivity (laser flash method), specific heat and density based on JIS R 1611, and it was 15 to 21 W / m · K.

  The color of the corrosion-resistant member of the present invention is N9.0 (white) or H (hue) is 10 YR or 2 in terms of the Munsell symbol HV / C (hue lightness / saturation) in the Munsell color system. .5Y, V (lightness) was 8.0 to 9.5, and C (saturation) was a color shown in the range of 0 to 2.

Next , as samples outside the scope of the present invention (comparative examples , sample Nos. 19 to 28 ), yttria (Y ₂ O ₃ ), the composition of the lanthanoid element oxide powder, metal elements (Si, Fe, Al, Ca, Mg) content, the specific surface area of the powder after drying, the degreasing temperature, the firing temperature, the heating rate, and the cooling rate were changed in the same manner as in the example, and the sintered body was evaluated and evaluated in the same manner as above. .

Tables 1 and 2 show the results of the sample of the present invention and the comparative example.

As is clear from Tables 1 and ₂ , the organic bond is obtained after the powder containing 99.5% by mass or more of Y ₂ O ₃ and the solvent are put in a mill and pulverized until the specific surface area becomes 1 m ² / g or more. The slurry to which the agent is added is spray-dried and granulated, and the resulting granule is used to obtain a molded body. This molded body is degreased at a temperature of 300 to 900 ° C., and the carbon content is 200 ppm or less. Further, in the atmosphere containing oxygen, the temperature is increased at a rate of temperature increase of 15 ° C./hour or less, held at 1500 to 2000 ° C. for 2 hours or more, and then decreased at a temperature decrease rate of 100 ° C./hour or less. Samples (Nos. 1-4, 8-18) obtained by firing the body can have a half-value width of the (222) plane attribute peak of cubic Y ₂ O ₃ as small as 0.4 ° or less. It was. In addition, Si, Fe, Al, Ca, Mg includes at least two metal elements including Si and Fe, Si content is 300 mass ppm or less in terms of SiO ₂ , Fe content is Fe ₂ O ₃ 50 mass ppm in terms of the following, the content of Al is less than 100 mass ppm in terms _{of Al} 2 _{O 3,} the content of Ca and Mg is 350 ppm by mass in total were CaO and MgO in terms respectively sample (No.8 -18), the full width at half maximum of the (222) plane attribute peak of cubic Y ₂ O ₃ was 0.21 to 0.26 °, which was even smaller. In addition, excellent characteristics were obtained with a dielectric loss tangent tan δ of 2 × 10 ⁻³ or less, no color unevenness, and an etching rate ratio of 4 nm / min or less. The crystallite diameter of the sample of the present invention was 5 to 100 nm. Further, the difference in the average crystal grain size between the surface vicinity and the deep part of the Y ₂ O ₃ sintered body is 30 μm or less, and the ratio of the content of the metal element in the vicinity of the surface to the deep part is 0.5 to 5. It was. Moreover, when the porosity of the sample of this invention was measured by the Archimedes method, all were 1% or less.

On the other hand, in the samples of comparative examples (Nos. 19 to 28), the half width of the (222) plane attribute peak of cubic Y ₂ O ₃ exceeded 0.4 °, and the etching rate was high. Further, not only the etching rate was high, but also the dielectric loss tangent tan δ was large or there was uneven color. Moreover, the sample of the comparative example had a crystallite diameter exceeding 200 nm.

It is a figure which shows the X-ray-diffraction pattern of the corrosion-resistant member of this invention. It is the schematic of the etching apparatus which is an application example of the corrosion-resistant member of this invention.

Explanation of symbols

1: Chamber 2: Clamp ring or focus ring 3: Lower electrode 4: Wafer 5: Induction coil

Claims (8)

A corrosion-resistant member used in a portion exposed to a corrosive gas containing at least a halogen element or plasma thereof, wherein the Y content is 99.5% by mass or more in terms of Y ₂ O ₃ and the carbon content is It is 100 mass ppm or less, and further contains two or more kinds of metal elements including at least Si and Fe among Si, Fe, Al, Ca, and Mg, and the content of Si is 300 mass ppm or less in terms of SiO ₂ . The content is 50 mass ppm or less in terms of Fe ₂ O ₃ , the Al content is 100 mass ppm or less in terms of Al ₂ O ₃ , and the Ca and Mg contents are 350 mass ppm or less in total in terms of CaO and MgO, respectively. there _Y 2 _{O 3} consists quality sintered body, a cubic _Y 2 _{O 3} in (222) plane half width of attribution peak from .21 to 0.26 ° by X-ray diffraction, the _{Y 2} With the difference between the average crystal grain size of the near-surface and the deep part of the ₃ quality sintered body (0.5 [mu] m or less of crystal and calculates excluded) is 30μm or less, containing the metal element of the near-surface for the deep A corrosion-resistant member, wherein the ratio of the amounts is 0.5 to 5. The corrosion-resistant member according to claim 1, wherein the lattice strain of the cubic Y ₂ O ₃ crystal is 0.2% or less.   The diameter of a crystallite is 5-100 nm on average, The corrosion-resistant member of Claim 1 or Claim 2 characterized by the above-mentioned. Said Y containing in terms _{of Y} 2 _{O 3} at least 99.9 wt%, the corrosion resistance member according to claim 1, wherein the half width is equal to or is from 0.21 to 0.25 ° . Corrosion resistant member according to claim 1, characterized in that it is ⁴ or less ^- a dielectric loss tangent at 1~5GHz is 1.6 × 10.   A porosity is 1% or less, The corrosion-resistant member in any one of Claims 1-5 characterized by the above-mentioned. A slurry preparation step of adding an organic binder after pulverizing a powder containing 99.5% by mass or more of Y ₂ O ₃ and a solvent into a mill until the specific surface area becomes 1 m ² / g or more, The slurry is spray-dried and granulated, and the content of metal elements in the granulated granule is 300 mass ppm or less in terms of SiO ₂ , Fe is 50 mass ppm or less in terms of Fe ₂ O ₃ , and Al is Al. 100 mass ppm or less in terms of ₂ O ₃ , Ca and Mg are 350 mass ppm or less in total in terms of CaO and MgO, respectively, and a molding step for producing a molded body using this granule; A degreasing step of degreasing at a temperature of ° C. to obtain a degreased body having a carbon content of 200 ppm or less, an oxygen partial pressure of 0.05 to 1 MPa, and an oxygen atmosphere containing 50% by volume or more of oxygen; It has a firing step in which the degreased body is fired by raising the temperature at a rate of temperature increase of not more than ° C / hour, holding at 1500 to 2000 ° C for 2 hours or more, and then decreasing the temperature at a rate of temperature decrease of 100 ° C / hour or less. A method for producing a corrosion-resistant member.   A member for a semiconductor / liquid crystal manufacturing apparatus, comprising the corrosion-resistant member according to claim 1.

Images