JP4119268B2 - Semiconductor manufacturing apparatus member and manufacturing method thereof - Google Patents

Description

（まとめ）
以上の結果より、石膏型を用いたスリップキャスティング法を利用して作製した実施例１〜実施例５の部材サンプルには、表面層にＣａリッチ層が形成されており、Ｃａリッチ層を有さない比較例１および比較例２に較べ、大幅にハロゲンガスに対する耐食性が向上していることが確認できた。
【００９１】
また、実施例１〜実施例５の部材サンプルの表面粗さも比較例１および２に較べ、明らかに大きくなっていることが確認できた。
【００９２】
また、Ｃａリッチ層の深さおよびＣａリッチ層におけるＣａ濃度は、石膏型原料として使用するα型半水石膏とβ型半水石膏との混合比で調整でき、β型半水石膏の混合比が高い程、Ｃａリッチ層が深くなり、Ｃａ濃度が高いことがわかった。また、Ｃａリッチ層が形成されている面の表面粗さＲａも、β型半水石膏の混合比が高い程、高いことが確認された。
【００９３】
なお、実施例１〜実施例５の部材サンプル内で、耐食性を比較すると、実施例１〜３の部材サンプルの値が実施例４，５の部材サンプルに対し明らかに良好であった。この結果より、石膏原料粉として、α型半水石膏とβ型半水石膏を５０：５０〜０：１００で混合したもの、表面から１ｍｍまでの深さにおけるＣａ濃度が４６０ｐｐｍ以上であるものにおいて特に良好な耐食性が得られていることが確認できた。
【００９４】
以上、実施の形態および実施例に沿って本発明の半導体製造装置用部材およびその製造方法について説明したが、本発明は、これらの実施の形態および実施例の記載に限定されるものでないことは明らかである。種々の改良および変更が可能なことは当業者には明らかである。
【００９５】
なお、本発明の半導体製造装置用部材は、上述したスリップキャスティング法を利用した本実施の形態の製造方法で作製することが望ましいが、この方法に限らず、ＣＩＰ法等を用いた成型体あるいは焼結体表面にＣａ含有アルミナ粉をコーティングする等の他の方法を用いて作製することも可能である。
【００９６】
【発明の効果】
以上に説明するように、本発明の半導体製造装置用部材は、ハロゲン系エッチング材に対し、高いエッチング耐性を有するため、部材寿命を延ばすことが可能である。
【００９７】
また、本発明の半導体製造装置用部材の製造方法によれば、プロセスの負荷を伴うことなく、本発明の半導体製造装置用部材を作製することが可能となる。また、パーティクルの発生を抑制できる部材を形成することができる。この部材を用いることで、半導体製造装置の反応容器内にスーパークリーン状態を作ることができるため、半導体プロセスの歩留まりを大幅に改善できる。
【図面の簡単な説明】
【図１】半導体製造装置と、この半導体製造装置で使用される、本発明の実施の形態に係る部材の例を示す装置概略図である。
【図２】本発明の実施の形態に係る内壁部材の構造を示す一部断面図である。
【符号の説明】
１・・・半導体製造装置
１０、２０・・・内壁部材
１２・・・Ｃａリッチ層
３０・・・リング部材
４０・・・基板
５０・・・基板台
５２・・・電極
５４・・・ヒータ
６０・・・高周波コイル[0001]
BACKGROUND OF THE INVENTION
The present invention relates to ceramics, and more particularly to an alumina sintered member used in a semiconductor manufacturing apparatus and a manufacturing method thereof.
[0002]
[Prior art]
Semiconductor manufacturing apparatuses such as thermal CVD, plasma CVD, and plasma etching apparatuses have a sealable reaction vessel that can maintain a low-pressure vacuum state. In the semiconductor manufacturing process, a reactive gas is introduced into a reaction vessel, and a thin film is formed on the wafer or etched by the thermal reaction or plasma reaction. As the reaction gas, a corrosive halogen-based gas is often used.
[0003]
For example, in a film forming apparatus, TiCl is used for forming a thin film for metal wiring.₄, MoCl₄And WF₆In plasma etching equipment, CF is used for etching Si films and various insulating films.₄, CCl₄, HF, ClF₃, And halogen gases such as HCl are used.
[0004]
Therefore, the members used in the reaction vessel, for example, the members constituting the inner wall of the reaction vessel and the various ring members installed around the substrate stand are sufficiently resistant to these halogen-based corrosive gases. It must be corrosive.
[0005]
Conventionally, an alumina sintered body is typically used as such a member for a semiconductor manufacturing apparatus (Patent Document 1). In order to produce such an alumina sintered body, usually, the raw materials are first blended, pulverized, granulated, and then molded by a method such as cold isostatic pressing (CIP). The molded body is fired, and after firing, the surface of the member is ground and polished together with the processing for obtaining a predetermined shape.
[0006]
[Patent Document 1]
JP 2001-44179 A
[0007]
[Patent Document 2]
JP-A-9-186229, paragraphs [0002] to [0003] and the like.
[0008]
[Problems to be solved by the invention]
However, the corrosion resistance of a member using a conventionally used alumina sintered body is not necessarily sufficient. In order to reduce the maintenance cost, it is desirable to reduce the replacement frequency of the members. For this purpose, further improvement in corrosion resistance is required.
[0009]
Further, in recent manufacture of LSI (Large Scale Integrated Circuit), generation of particles generated in a reaction vessel of a semiconductor manufacturing apparatus has become a problem with the demand for miniaturization. In a reaction vessel where film formation or etching is performed, a reaction product adheres to an inner wall member or the like. When the thickness of the adhesion film exceeds a certain level, the film is easily peeled off and generates particles. The particles dropped on the substrate in this manner cause disconnection or short circuit when forming the wiring pattern, and reduce the yield of the semiconductor process.
[0010]
An object of the present invention has been made in view of the above-described conventional problems, and is to provide a member for a semiconductor manufacturing apparatus and a manufacturing method thereof that can further improve the corrosion resistance.
[0011]
Another object of the present invention is to provide a member for a semiconductor manufacturing apparatus capable of suppressing the generation of particles and a method for manufacturing the same.
[0012]
[Means for Solving the Problems]
  The semiconductor manufacturing apparatus member of the present invention is a sintered body mainly composed of alumina, and at least a surface layer including a surface exposed in the reaction vessel at the time of use,The amount of Ca gradually decreases from the surface toward the inside of the sintered body.Ca rich layerAnd the Ca concentration in the region from the surface to a depth of 1 mm is at least 280 ppm or more.
[0013]
According to the characteristics of the semiconductor manufacturing apparatus member of the present invention, when the surface of the member is exposed to a halogen gas, Ca in the Ca-rich layer reacts with the halogen to generate chemically stable calcium halide. Corrosion resistance against gas can be greatly improved. Note that calcium halide may be generated in advance in the Ca-rich layer. Further, since the Ca-rich layer is formed only on the surface layer of the member, problems such as non-uniformity of crystal grains of the alumina sintered body accompanying Ca content do not occur inside the sintered body.
[0014]
  In the member for a semiconductor manufacturing apparatus having the characteristics of the present invention, the Ca concentration at a distance from the surface to a depth of 1 mm is more preferably 460 ppm or more. In the present specification, ppm means mass ppm.
[0015]
The calcium halide produced by the reaction with the halogen gas increases the coverage of the surface of the alumina sintered body with calcium halide as the Ca concentration in the surface layer increases, so that the corrosion resistance of the member can be further improved. it can. If the Ca concentration in the region extending from the surface to a depth of 1 mm is 460 ppm or more, the life of the member with respect to the halogen gas can be improved by about twice.
[0016]
In the member for a semiconductor manufacturing apparatus having the characteristics of the present invention, it is preferable that the average surface roughness of the surface exposed in the reaction container at the time of use is 2 to 5 μm. In this case, since minute unevenness exists on the surface of the member exposed in the reaction vessel, the peeling of the reaction product adhering to the surface of the member can be suppressed by the uneven anchor effect, so that generation of particles can be prevented.
[0017]
In addition, it is preferable that the member for a semiconductor manufacturing apparatus having the characteristics of the present invention is manufactured using a slip casting method using a gypsum mold, and Ca in the Ca rich layer is mixed into the gypsum mold. .
[0018]
Further, in the member for a semiconductor manufacturing apparatus having the characteristics of the present invention, the surface exposed in the reaction vessel in use maintains the surface shape immediately after sintering obtained by firing the molded body. It is preferable.
[0019]
The method for manufacturing a member for a semiconductor manufacturing apparatus according to the present invention includes a step of producing a slurry containing alumina, a step of casting the slurry into a gypsum mold, a step of releasing the molded body from the gypsum mold, and at least a final process. When the product is used in the semiconductor manufacturing apparatus, the surface exposed in the reaction vessel is baked in a state where the surface shape of the molded body is maintained immediately after release, and at least the final product is a semiconductor manufacturing apparatus. The surface exposed in the reaction vessel when used in the inside is characterized by having a step of performing processing necessary for the final product shape while maintaining the surface shape immediately after firing.
[0020]
According to the characteristics of the production method of the present invention, the Ca component contained in the gypsum is mixed into the surface layer of alumina during casting. When the final product is used in the semiconductor manufacturing apparatus, the surface exposed in the reaction vessel is maintained as it is with the uneven surface shape immediately after the casting process and the baking process. For this reason, a Ca rich layer is formed on the surface layer of the member of the final product, and irregularities are formed on the surface. When the Ca-rich layer is exposed to a halogen gas in the semiconductor manufacturing apparatus, the Ca-rich layer changes to calcium halide having extremely high corrosion resistance, and greatly improves the durability of alumina. Moreover, even if the reaction product generated in the semiconductor manufacturing apparatus adheres to such a member, since the unevenness exists on the surface of the member, the peeling of the reaction product is suppressed by the anchor effect, resulting in the number of particles on the substrate. Can be reduced.
[0021]
Further, if there is a large amount of Ca in the sintered body, abnormal crystal growth of alumina may occur. However, in the above manufacturing method, the Ca-rich layer is formed only on the surface layer of alumina. A sintered body of alumina having a uniform diameter can be formed.
[0022]
In the method of manufacturing a member for a semiconductor manufacturing apparatus having the characteristics of the present invention, a step of halogenating the surface exposed in the reaction vessel at least when the final product is used in the semiconductor manufacturing apparatus after the firing step. You may have. In this case, a halogenation treatment by the user is not required when used, and more stable corrosion resistance can be provided.
[0023]
In the method for manufacturing a member for a semiconductor manufacturing apparatus having the characteristics of the present invention, the gypsum mold is α-type semi-hydraulic gypsum or β-type hemihydrate gypsum, or α-type hemihydrate gypsum and β-type hemihydrate gypsum. It is preferable that it is what was produced using what was made as gypsum raw material powder. Furthermore, it is more preferable that the gypsum raw material powder is a gypsum raw material powder obtained by mixing α-type hemihydrate gypsum and β-type hemihydrate gypsum at a mass ratio of 50:50 to 0: 100.
[0024]
Hemihydrate gypsum is hydrophilic because it contains water in its components, and has high water absorption. In addition, β-type hemihydrate gypsum has higher water absorption than α-type hemihydrate gypsum. The higher the water absorption, the more Ca can be mixed into the alumina molded body surface layer during casting, and the Ca-rich layer can be formed more reliably. On the other hand, since β-type hemihydrate gypsum is brittle, mixing the α-type hemihydrate gypsum can give good strength to the gypsum mold.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a member for a semiconductor manufacturing apparatus according to an embodiment of the present invention will be described with reference to the drawings.
[0026]
FIG. 1 shows a partial configuration example of a reaction vessel of a semiconductor manufacturing apparatus. Here, a plasma etching apparatus is illustrated as an example of a semiconductor manufacturing apparatus. However, a semiconductor manufacturing apparatus member according to the present embodiment described below is not limited to a plasma etching apparatus, but includes plasma cleaning, plasma CVD, and plasma oxidation treatment. The present invention is intended for members installed in reaction vessels of various plasma processing apparatuses such as plasma nitriding processing, or various semiconductor manufacturing apparatuses such as thermal CVD and sputtering apparatus that do not use plasma.
[0027]
As shown in FIG. 1, for example, a reaction vessel 1 of a plasma etching apparatus includes a cylindrical inner wall member 20 and a dome-shaped inner wall member 10 provided on the cylindrical inner wall member 20. A high frequency coil 60 for generating plasma is installed around the outer periphery of the dome-shaped inner wall member 10.
[0028]
A substrate 40 is installed on a substrate stand 50 below the reaction vessel 1. An annular ring member 30 is installed around the substrate table 50 for the purpose of preventing damage to the surface of the substrate table 50. The substrate table 50 may include an electrostatic chuck electrode 52 and a heater 54 so as to have an electrostatic chuck function for fixing the substrate or a heater function for heating the substrate.
[0029]
As a member according to the embodiment of the present invention, all members used in reaction vessels of various semiconductor manufacturing apparatuses are targeted. Typically, the inner wall members 10 and 20 used in the reaction vessel, the ring member 30 and the like. The shape of the inner wall member 10 or 20 may be various shapes depending on the shape of the semiconductor manufacturing apparatus, and is not limited to the dome shape or the annular shape as illustrated, but may be a cylindrical shape or a rectangular parallelepiped shape. It may be an integrated type or a combination of a plurality of parts. The ring member 30 may also be a combination of a plurality of ring members.
[0030]
FIG. 2 is a partial cross-sectional view of the inner wall member 10 according to the present embodiment. The inner wall member 10 is formed of a sintered body containing alumina as a main component, and has a Ca concentration higher than the inside of the sintered body at least on the surface layer exposed in the reaction vessel when using the final product. A rich layer 12 is provided. Note that the Ca-rich layer 12 may be formed not only on the surface exposed in the reaction vessel but also on the surface layer of the other surface.
[0031]
The Ca rich layer 12 is a layer containing at least a Ca concentration higher than the Ca concentration inside the alumina sintered body. Or it can also be called the layer containing Ca concentration higher than the Ca concentration contained in the alumina raw material of an alumina sintered compact.
[0032]
Other members such as the inner wall member 20 and the ring member 30 shown in FIG. 1 have the same structure as the inner wall member 10 and have Ca-rich layers 22 and 32, respectively.
The depth of the Ca-rich layer 12 is not particularly limited, but when the alumina sintered body contains a large amount of Ca, when the alumina is sintered, abnormal crystal growth of alumina occurs in the sintering process. It is difficult to obtain a uniform alumina particle size. Therefore, the depth of the Ca rich layer 12 is desirably shallow due to such process requirements, and is preferably 1.5 mm or less, more preferably 0.9 mm or less.
[0033]
After the member according to the present embodiment is installed in the semiconductor manufacturing apparatus, Cl is used for cleaning the semiconductor substrate in the reaction vessel 1 or for thin film etching.₂, HCl, BCl₃, ClF₃, NF₃, CF₄, WF₆When a halogen-based corrosive gas such as Ca is introduced, Ca in the Ca-rich layer reacts with these halogen gases, and CaCl₂, CaF₂Calcium halide having higher corrosion resistance than alumina such as alumina is formed on the surface layer of the member. Once calcium halide is generated on the surface of the member, the lifetime of the member is improved due to its high corrosion resistance.
[0034]
In addition, before installing a member in a semiconductor manufacturing apparatus, the surface of a member may be separately halogenated to form calcium halide in advance. For example, the fluoride treatment described later may be performed to generate calcium fluoride having high corrosion resistance in advance. Since a coating of calcium halide can be formed on the surface of the member in advance, there is no need for a halogenation treatment by the user, and calcium fluoride with a high corrosion resistance effect is formed under certain conditions, making it more stable and reliable. Can provide corrosion resistance.
[0035]
The Ca concentration of the Ca-rich layer 12 is not particularly limited. For example, if it is at least 280 ppm in a depth region of 1 mm from the surface, the corrosion resistance can be improved as compared with the conventional alumina sintered member not including the Ca-rich layer 12. If it is 460 ppm or more in a depth region of 1 mm from the surface, the etching rate with respect to the halogen gas can be suppressed to ½ or less of the conventional one, and the corrosion resistance can be greatly improved. Moreover, if it is 280 ppm-1100 ppm, it can produce using the manufacturing method using the slip casting method using a plaster mold so that it may mention later.
[0036]
On the other hand, as shown in the example of the inner wall member 10 in FIG. 2, each member that is an embodiment of the present invention has at least a surface exposed in the reaction vessel having irregularities with an average surface roughness of 2 to 5 μm. It is preferable. Thus, if there are minute irregularities on the surface, even if the reaction product produced by the reaction in the reaction vessel adheres to the member surface, the physical anchor effect due to the irregularity causes the reaction product and the member surface to Since the adhesiveness is increased, peeling of the reaction product is suppressed, and generation of particles can be prevented. Therefore, if such a member is used, the cleanliness in this reaction container can be maintained high, and the yield of the semiconductor process can be increased.
[0037]
The surface roughness of the member surface can be positively formed by blasting the member surface. However, as will be described later, the surface roughness of the member surface generated in the casting process and the firing process is positively Can also be used.
[0038]
Next, a method for manufacturing a member for a semiconductor manufacturing apparatus according to an embodiment of the present invention will be described. The manufacturing method according to the present embodiment has a main feature of performing molding using a slip casting method using a plaster mold.
[0039]
First, alumina powder as a raw material, a dispersion material, and water are mixed to produce an aqueous slurry (mud). For example, a dispersion material is dissolved in ion-exchanged water, and alumina powder is further mixed into this aqueous solution, and mixed using a pot mill or a trommel to prepare a slurry. In order to make the penetration depth of Ca from the gypsum mold into the alumina molded body as small as possible in the subsequent casting process, it is desirable to increase the viscosity of the alumina-containing slurry. For example, the moisture in the alumina-containing slurry is 16.5% by mass or less. A binder is added to the slurry, and further mixed, and vacuum defoaming is performed. If necessary, a sintering aid or the like may be added to the slurry.
[0040]
Next, a gypsum mold is prepared, and the slurry is poured into this and cast. By this casting process, Ca, which is a gypsum component, is mixed into the surface layer of the alumina molded body having a depth of about 0.6 mm to 1.5 mm to form a Ca rich layer.
[0041]
The gypsum material used for the gypsum mold is generally anhydrous gypsum (CaSO₄) And hemihydrate gypsum (CaSO₄・ 1 / 2H₂O), but in the slip casting method according to the present embodiment, it is preferable to use hemihydrate gypsum having high water absorption. By using a highly water-absorbing gypsum material, the ion exchange reaction between the gypsum mold and the alumina molded body is promoted during casting, and the gypsum component Ca in the gypsum is easily mixed into the alumina molded body. it can.
[0042]
Hemihydrate gypsum includes α-type hemihydrate gypsum and β-type hemihydrate gypsum. The α type has acicular crystals and high strength, and the β type has plate crystals and lower strength, but has a higher water absorption capacity than the α type. In the manufacturing method of the present embodiment, it is possible to use only one of α-type and β-type as a gypsum raw material. In order to promote mixing, it is preferable to use a mixture of α-type hemihydrate gypsum and β-type hemihydrate gypsum as a gypsum raw material. In addition, when using β-type hemihydrate gypsum with high water absorption, Ca is mixed deeper into the surface layer of the alumina molded body at the time of casting. It is desirable to suppress this.
[0043]
For example, α-type hemihydrate gypsum and β-type hemihydrate gypsum are mixed at a mass ratio of about 50:50 to 0: 100, more preferably about 30:70, and water is added to add dihydrate gypsum (CaSO₄・ 2H₂O), which is processed into a gypsum mold and dried to remove excess water, is used as the gypsum mold for the member.
[0044]
At the time of casting, the gypsum mold absorbs moisture in the slurry, and some gypsum components dissolve in the moisture and penetrate into the grain boundaries on the surface of the molded alumina molded body to physically surface the alumina molded body surface layer. Adsorbs strongly to. In addition, these Ca-containing gypsum components are peeled off together with the alumina molded body when the alumina molded body is released from the gypsum mold, and become a part of the alumina molded body. Thus, Ca is mixed from the gypsum mold into the surface layer of the alumina molded body, and as the gypsum is mixed and peeled, irregularities are formed on the surface of the alumina molded body.
[0045]
Thus, a Ca rich layer is formed on the surface layer having a depth of about 0.6 mm to 1.5 mm of the alumina molded body by the casting step. Further, irregularities having a surface roughness of 1.5 μm to 5 μm, more preferably 2 μm to 5 μm can be formed on the surface of the alumina molded body. In order to increase the surface roughness, if the rough concavo-convex surface is formed in advance on the inner surface of the gypsum mold using sandblast, the concavo-convex surface can be more reliably formed on the surface of the alumina molded body.
[0046]
Thereafter, if necessary, the molded body may be subjected to necessary processing for forming screw holes or the like, but at least the surface of the molded body that becomes an exposed surface in the reaction vessel in the final product is subjected to a casting process. Grinding or the like is not performed so that the formed surface shape can be maintained as it is.
[0047]
The alumina molded body released from the gypsum mold is transferred to a drying furnace to remove moisture. Further, the alumina molded body is transferred to a degreasing furnace and slowly heated to about 500 ° C. to burn the internal binder. Furthermore, it is also possible to perform calcination for giving strength at 1000 ° C. to 1300 ° C.
[0048]
Finally, firing is performed for several hours to five hours under a temperature condition of about 1500 to 1650 ° C. in an atmospheric pressure oxidizing atmosphere to obtain an alumina sintered body. During sintering, if a large amount of Ca is dispersed inside the sintered body, abnormal crystal growth may occur due to the presence of Ca, but the Ca-rich layer is formed only on the surface layer of the member. Therefore, a dense structure with a uniform particle size can be formed inside the alumina sintered body.
[0049]
After the firing step, the surface of the alumina sintered body is polished in the conventional process, but in the manufacturing method according to the present embodiment, at least the member surface that is the exposed surface in the reaction vessel in the final product is fired. In order to maintain the surface shape obtained by the above, grinding or polishing is not performed, but only other necessary processing is performed.
[0050]
As described above, the member according to the present embodiment does not grind or polish at least the exposed surface of the alumina sintered body in the reaction vessel, so that crystal cracking or dropout of crystal grains occurs due to grinding. Absent. Therefore, it is possible to prevent the generation of particles such as falling particles generated from the member itself.
[0051]
In this way, the semiconductor manufacturing apparatus member according to the present embodiment can be obtained, which has a Ca-rich layer on the surface of the sintered body serving as an exposed surface in the reaction vessel and has irregularities on the surface. The Ca-rich layer formed on the surface layer of the member changes into stable calcium halide when exposed to the halogen gas in the semiconductor manufacturing apparatus, so that the lifetime as a member can be greatly improved. Moreover, even if the reaction product adheres to the surface of the member, the adhered reaction product is difficult to peel off due to the anchor effect of the unevenness of the surface, so that generation of particles can be suppressed.
[0052]
In the member manufacturing method according to the present embodiment, after the firing step, the surface of the member may be exposed to a halogen gas to positively form calcium halide. Although it does not specifically limit as a fluorination process, For example, after heating a member beforehand and removing the water | moisture content in a member, in inert gas containing 60% or more of fluorine gas, it heat-processes at 300 to 500 degreeC for 1 hour- 10 hours is recommended.
[0053]
As described above, in the method for manufacturing a member for a semiconductor manufacturing apparatus according to the present embodiment, by using a slip casting method using a gypsum mold, Ca, which is a gypsum component, is converted into alumina from the gypsum mold during casting. By mixing in the surface layer of the molded body, a Ca-rich layer can be formed on the member surface layer. Further, by not processing the fired surface, it is possible to form irregularities on the member surface without burdening the manufacturing process. As a result, it is possible to provide a member for a semiconductor manufacturing apparatus that has high corrosion resistance and can prevent generation of particles.
[0054]
【Example】
Examples of the present invention and comparative examples will be described below. The conditions and results of each example and comparative example are shown in Table 1.
[0055]
Example 1
In Example 1, a member sample made of an alumina sintered body of 100 mm × 100 mm × 20 t was produced by the following procedure.
[0056]
First, a polycarboxylic acid type polymer surfactant as a dispersant was added to ion-exchanged water to prepare an aqueous solution. To this aqueous solution, a commercially available alumina powder having a purity of 99.5% and an average particle diameter of 0.4 μm was added and mixed with a trommel to prepare a slurry. The mass ratio between the alumina powder and the dispersant was 100: 0.6. The mass ratio of ion exchange water and alumina powder was 20:80. Further, an acrylic resin was added as a binder to this slurry, and then defoamed. The mass ratio between the alumina powder and the acrylic resin was 100: 2.
[0057]
A mixture of α-type hemihydrate gypsum and β-type hemihydrate gypsum at a mass ratio of 30:70 is used as a gypsum raw material powder, and water is further added to produce dihydrate gypsum, which is used to produce a gypsum mold. did. The slurry produced by the above-described method was poured into a gypsum mold that had been dried to remove excess water, and the meat was made to fill. When the inking to the center was completed, the molded body was released. The molded body was put in a drier, the temperature was gradually raised, and finally the water was heated to 120 ° C. to remove moisture.
[0058]
Next, the molded body was moved into a degreasing furnace, the temperature was slowly raised to 500 ° C., and organic substances such as an internal binder were burned and removed. Furthermore, after calcining at 1000 ° C. to give an appropriate strength, the molded body was transferred to a firing furnace and baked at 1600 ° C. for 3 hours. Thus, a member sample made of an alumina sintered body was obtained. The surface immediately after firing was left as it was, and grinding or polishing was not performed.
[0059]
About the surface layer of the produced member sample, when the analysis in the depth direction was performed using an EPMA (Electron Probe Micro analyzer) method, the surface layer of the alumina sintered body from the surface to a depth of about 1.1 mm was obtained. It was confirmed that a Ca rich layer having a higher Ca concentration than the inside of the sintered body was formed. When the impurity concentration in this region was measured using ICP (Inductively Coupled Plasma) emission analysis, the Ca-rich layer contained about 630 ppm of Ca, and the Ca concentration in the region from the surface to a depth of 1 mm was about 600 ppm. It was confirmed that.
[0060]
About the produced member sample, the corrosion resistance test with respect to fluorine gas was done in the following procedure. That is, first, the surface of the member sample was masked with a corrosion-resistant polyimide resin tape to expose only the 10 mm square surface. The member sample after this masking was affixed on a Φ200 mm Si wafer. The Si wafer to which this member sample was attached was placed on a stage in an inductively coupled plasma apparatus having a sealable reaction vessel, and the inside of the reaction vessel was purged with nitrogen gas four times.^-5torr (5.33 × 10^-3The pressure was reduced to Pa). Then NF₃A gas of 100 sccm and an Ar gas of 140 sccm were introduced into the reaction vessel, respectively, and the pressure in the reaction vessel was set at 0.1 Torr. A self-bias voltage (Vdc) of 450 V was applied to generate ICP plasma in the reaction vessel. In this way, the masked member sample is NF for about 2 hours.₃The sample was exposed to plasma and subjected to a corrosion resistance test. After this, the power was turned off and the reaction vessel was purged with nitrogen gas. Then, the sample was taken out and the polyimide resin tape used for masking was peeled off.₃The etching depth was determined by measuring the level difference between the plasma exposure surface and the masking surface with a surface roughness meter. As a result, the etching rate on the exposed surface of the member sample is 0.6 μm / hr, and the etching rate of Si wafer under the same conditions is 25.0 μm / hr, or the etching rate of single crystal quartz (Quartz) is 5.1 μm / hr. In comparison, it was found that the etching rate was extremely slow.
[0061]
Similarly, the corrosion resistance test of the member sample with respect to chlorine gas was conducted. In the reaction vessel, BCl₃, Cl₂And Ar gas were introduced at 100 sccm, 100 sccm and 50 sccm, respectively. The other conditions were the same as in the fluorine gas corrosion resistance test. As a result, the etching rate on the exposed surface of the member sample was 1.1 μm / hr, which was found to be very slow compared to the etching rate of 1.8 μm / hr for single crystal quartz (Quartz) under the same conditions. .
[0062]
From the corrosion resistance test results of fluorine gas and chlorine gas, it was confirmed that the member sample of Example 1 had extremely high corrosion resistance to halogen gas.
[0063]
About the produced member sample, it measured about bending strength and bulk density. The bending strength was measured using a four-point bending method at room temperature based on JIS R1601. The result was 330 MPa, and sufficient strength was obtained. The bulk density was 3.92 g / cc as measured using the Archimedes method.
[0064]
Moreover, when the surface roughness Ra of the surface in which the Ca rich layer was formed was measured, it was 2.5 to 4 μm.
[0065]
(Example 2)
A member sample of Example 2 was produced in substantially the same procedure as in Example 1. The difference from Example 1 is that only β-type hemihydrate gypsum is used as a gypsum-type raw material. That is, in Example 2, water was added to β-type hemihydrate gypsum to make dihydrate gypsum, which was used to produce a gypsum mold. The other molding conditions and firing conditions were the same as in Example 1.
[0066]
About the produced member sample, it measured about Ca density | concentration of a surface layer, corrosion resistance, bending strength, and bulk density. The measurement conditions were the same as in Example 1.
[0067]
The depth of the Ca rich layer was about 1.5 mm. Further, the Ca concentration in the Ca rich layer was 1600 ppm. Further, the Ca concentration in the region from the surface to a depth of 1 mm is 1100 ppm, and it can be confirmed that the Ca rich layer having a high Ca concentration is formed deeper in the member sample of Example 2 than in Example 1. It was.
[0068]
Further, in the corrosion resistance test, the chlorine gas showed almost the same corrosion resistance as that of Example 1, but it was confirmed that the etching rate was slower than that of Example 1 and that the fluorine gas showed higher corrosion resistance. It was done.
[0069]
The bending strength and bulk density were 330 MPa and 3.92 g / cc as in Example 1. Moreover, when the surface roughness Ra of the surface in which the Ca rich layer was formed was measured, it was 3 to 5 μm.
[0070]
(Example 3)
A member sample of Example 3 was produced in substantially the same procedure as in Example 1. The difference from Example 1 is that a gypsum type raw material obtained by mixing α-type hemihydrate gypsum and β-type hemihydrate gypsum at a mass ratio of 50:50 was used. That is, in Example 3, α-type hemihydrate gypsum and β-type hemihydrate gypsum were mixed at the above mass ratio, and water was added to make dihydrate gypsum, thereby producing a gypsum mold. The other molding conditions and firing conditions were the same as in Example 1.
[0071]
About the produced member sample, it measured about Ca density | concentration of a surface layer, corrosion resistance, bending strength, and bulk density. The measurement conditions were the same as in Example 1.
[0072]
The depth of the Ca rich layer was about 0.9 mm. Further, the Ca concentration in the region from the surface to a depth of 1 mm is 460 ppm, and it can be confirmed that the Ca-rich layer is formed shallower in the member sample of Example 3 than in Example 1 and Example 2. It was. In the corrosion resistance test, the corrosion resistance to fluorine gas and chlorine gas was almost the same as in Example 1 and Example 2.
[0073]
The bending strength and bulk density were 340 MPa and 3.92 g / cc, respectively. Moreover, it was 2-3 micrometers when surface roughness Ra of the surface in which Ca rich layer was formed was measured.
[0074]
Example 4
A member sample of Example 4 was produced in substantially the same procedure as in Example 1. The difference from Example 1 is that a mixture of α-type hemihydrate gypsum and β-type hemihydrate gypsum at a mass ratio of 70:30 was used as the gypsum-type raw material. That is, in Example 4, α-type hemihydrate gypsum and β-type hemihydrate gypsum were mixed at the above-described mass ratio, and water was added thereto to make dihydrate gypsum, thereby producing a gypsum mold. The other molding conditions and firing conditions were the same as in Example 1.
[0075]
About the produced member sample, it measured about Ca density | concentration of a surface layer, corrosion resistance, bending strength, and bulk density. The measurement conditions were the same as in Example 1.
[0076]
The depth of the Ca rich layer was about 0.6 mm. Further, the Ca concentration in the region from the surface to a depth of 1 mm is 300 ppm, and it can be confirmed that the Ca rich layer with a high Ca concentration is formed shallower in the member sample of Example 4 than in Example 3. It was.
[0077]
Moreover, in the corrosion resistance test with respect to fluorine gas and chlorine gas, the etching rate was faster than in Examples 1 to 3. However, as compared with Comparative Examples 1 and 2 described later, it was confirmed that the etching rate was sufficiently slow and the corrosion resistance was higher than that of the conventional product.
[0078]
The bending strength and bulk density were 330 MPa and 3.92 g / cc, respectively. Moreover, it was 1.5-2.5 micrometers when surface roughness Ra of the surface in which the Ca rich layer was formed was measured.
[0079]
(Example 5)
A member sample of Example 3 was produced under substantially the same conditions as in Example 1. The difference from Example 1 is that only α-type hemihydrate gypsum was used as the gypsum-type raw material. That is, in Example 5, water was added to α-type hemihydrate gypsum to form dihydrate gypsum, and thus a gypsum mold was produced. Other molding conditions and firing conditions were the same as in Example 1.
[0080]
The depth of the Ca-rich layer and the Ca concentration of the produced member sample were measured using the EPMA method in the same manner as in Example 1. As a result, it was confirmed that a Ca-rich layer was formed in a region having a depth of 0.6 mm from the surface. The Ca concentration in the Ca rich layer was 380 ppm. Further, the Ca concentration in the region from the surface to a depth of 1 mm was 280 ppm, which was a lower concentration than the sample members of Examples 1 to 4.
[0081]
Moreover, in the corrosion resistance test with respect to fluorine gas and chlorine gas, the etching rate was faster than in Examples 1 to 3. However, as compared with Comparative Examples 1 and 2 described later, it was confirmed that the etching rate was sufficiently slow and the corrosion resistance was higher than that of the conventional product.
[0082]
Moreover, it was 1.5-2.5 micrometers when surface roughness Ra of the surface in which the Ca rich layer was formed was measured.
[0083]
(Comparative Example 1)
A member sample of Comparative Example 1 was produced under the same conditions as in Example 1. However, the member sample of Comparative Example 1 was made up to an alumina sintered body under the same conditions as in Example 1, and then the surface was polished by 2 mm or more.
[0084]
About the produced member sample, it measured about Ca density | concentration of a surface layer, corrosion resistance, bending strength, and bulk density. The measurement conditions were the same as in Example 1.
[0085]
The Ca-rich layer does not exist by being ground by grinding, and the Ca concentration in the region from the surface to a depth of 1 mm is 160 ppm, which is confirmed to be considerably lower than the member samples of Examples 1 to 5. It was done. In the corrosion resistance test, the etching rate was 1.3 μm / hr and 2.6 μm / hr, which were considerably faster than those in Examples 1 to 5 for both fluorine gas and chlorine gas. The bending strength and bulk density were 360 MPa and 3.92 g / cc, respectively.
[0086]
(Comparative Example 2)
The member sample of Comparative Example 2 was produced by using a commonly used cold isostatic press (CIP) molding method without using the slip casting method. The size of the member sample is the same as in Example 1.
[0087]
First, alumina raw material powder and an acrylic binder were mixed and granulated, and then the granulated powder was filled into a CIP press machine and molded. Thereafter, the molded body was transferred to a degreasing furnace, and organic substances such as an internal binder were burned and removed under the same conditions as in Example 1. Preliminary firing was performed at 1000 ° C., and further, firing was performed in air at 1600 ° C. for 3 hours to obtain a member sample that was an alumina sintered body. The member surface was not ground or polished.
[0088]
About the produced member sample, it measured about Ca density | concentration of a surface layer, corrosion resistance, bending strength, and bulk density. The measurement conditions were the same as in Example 1.
[0089]
No Ca-rich layer was present in the surface layer, and the Ca concentration in the surface layer from the surface to a depth of 1 mm was 140 ppm. This value was not different from the Ca concentration contained as an impurity in the alumina raw material, and was confirmed to be a considerably lower concentration compared to the member samples of Examples 1 to 5. In the corrosion resistance test, the etching rates were 1.1 μm / hr and 2.4 μm / hr, respectively, faster than those in Examples 1 to 5 for both fluorine gas and chlorine gas. When compared with Examples 1 to 5, it was confirmed that the corrosion resistance to halogen was inferior. The bending strength and bulk density were 380 MPa and 3.92 g / cc.
[0090]
[Table 1]

(Summary)
From the above results, the member samples of Examples 1 to 5 manufactured using the slip casting method using a gypsum mold have a Ca rich layer formed on the surface layer, and have a Ca rich layer. It was confirmed that the corrosion resistance to the halogen gas was significantly improved as compared with Comparative Example 1 and Comparative Example 2 that were not present.
[0091]
Moreover, it has confirmed that the surface roughness of the member sample of Example 1- Example 5 was clearly large compared with Comparative Example 1 and 2. FIG.
[0092]
The depth of the Ca-rich layer and the Ca concentration in the Ca-rich layer can be adjusted by the mixing ratio of the α-type hemihydrate gypsum and β-type hemihydrate gypsum used as the gypsum-type raw material. It was found that the higher the value, the deeper the Ca-rich layer and the higher the Ca concentration. It was also confirmed that the surface roughness Ra of the surface on which the Ca-rich layer was formed was higher as the mixing ratio of β-type hemihydrate gypsum was higher.
[0093]
In addition, when the corrosion resistance was compared in the member samples of Examples 1 to 5, the values of the member samples of Examples 1 to 3 were clearly better than those of Examples 4 and 5. From this result, as the gypsum raw material powder, α-type hemihydrate gypsum and β-type hemihydrate gypsum mixed at 50:50 to 0: 100, and the Ca concentration at a depth of 1 mm from the surface is 460 ppm or more It was confirmed that particularly good corrosion resistance was obtained.
[0094]
As mentioned above, although the member for semiconductor manufacturing apparatuses of this invention and its manufacturing method were demonstrated along embodiment and an Example, this invention is not limited to description of these embodiment and an Example. it is obvious. It will be apparent to those skilled in the art that various modifications and variations can be made.
[0095]
The member for a semiconductor manufacturing apparatus of the present invention is preferably manufactured by the manufacturing method of the present embodiment using the slip casting method described above, but is not limited to this method, and a molded body using the CIP method or the like It is also possible to produce by using other methods such as coating the surface of the sintered body with Ca-containing alumina powder.
[0096]
【The invention's effect】
As described above, since the member for a semiconductor manufacturing apparatus of the present invention has high etching resistance with respect to a halogen-based etching material, the member life can be extended.
[0097]
Moreover, according to the manufacturing method of the member for semiconductor manufacturing apparatuses of this invention, it becomes possible to produce the member for semiconductor manufacturing apparatuses of this invention, without being accompanied by the process load. In addition, a member capable of suppressing the generation of particles can be formed. By using this member, a super clean state can be created in the reaction vessel of the semiconductor manufacturing apparatus, so that the yield of the semiconductor process can be greatly improved.
[Brief description of the drawings]
FIG. 1 is a schematic view showing a semiconductor manufacturing apparatus and examples of members used in the semiconductor manufacturing apparatus according to an embodiment of the present invention.
FIG. 2 is a partial cross-sectional view showing a structure of an inner wall member according to the embodiment of the present invention.
[Explanation of symbols]
1 ... Semiconductor manufacturing equipment
10, 20 ... inner wall member
12 ... Ca rich layer
30 ... Ring member
40 ... Substrate
50 ... Substrate stand
52 ... Electrodes
54 ... Heater
60 ... High frequency coil

Claims (12)

A sintered body mainly composed of alumina,
At least, the surface layer including a surface exposed to the reaction vessel during use, have a Ca-rich layer weight Ca is gradually reduced toward the inside of the sintered body from the surface, the depth of 1mm from the surface A member for a semiconductor manufacturing apparatus, characterized in that a Ca concentration in a region leading to is at least 280 ppm or more. The member for a semiconductor manufacturing apparatus according to claim 1 , wherein a Ca concentration in a region extending from the surface to a depth of 1 mm is 460 ppm or more. The member for a semiconductor manufacturing apparatus according to claim 2 , wherein a Ca concentration in a region extending from the surface to a depth of 1 mm is 460 ppm or more and 1100 ppm or less. The said Ca rich layer is 1.5 mm or less in thickness, The member for semiconductor manufacturing apparatuses of any one of Claims 1-3 characterized by the above-mentioned. The said Ca rich layer contains a calcium halide, The member for semiconductor manufacturing apparatuses of any one of Claims 1-4 characterized by the above-mentioned. The member for a semiconductor manufacturing apparatus according to claim 1, wherein an average surface roughness of the surface is 2 μm to 5 μm. The member for a semiconductor manufacturing apparatus is molded using a slip casting method using a gypsum mold, the Ca-rich layer can be of any claim 1-6, characterized in that they contain Ca which is mixed from the gypsum mold A member for a semiconductor manufacturing apparatus according to claim 1. The member for a semiconductor manufacturing apparatus according to claim 7 , wherein the surface has a surface shape immediately after sintering obtained by firing a molded body as it is. Producing a slurry containing alumina;
Pouring the slurry into a plaster mold and casting;
A step of releasing the molded body from the gypsum mold;
At least when the final product is used in a semiconductor manufacturing apparatus, the surface exposed in the reaction vessel is subjected to the firing of the molded body while maintaining the surface shape of the molded body immediately after the mold release; and
And a step of performing necessary processing while maintaining the surface shape immediately after the baking for the surface exposed in the reaction vessel when the final product is used in the semiconductor manufacturing apparatus. A method for manufacturing a device member. After the step of performing the firing,
10. The method for manufacturing a member for a semiconductor manufacturing apparatus according to claim 9 , further comprising a step of halogenating a surface exposed in the reaction vessel when the final product is used in the semiconductor manufacturing apparatus. The gypsum mold is made using α-type hemihydrate gypsum or β-type hemihydrate gypsum, or a mixture of the α-type hemihydrate gypsum and the β-type hemihydrate gypsum as the gypsum raw material powder. method of manufacturing a member for a semiconductor manufacturing apparatus according to claim 9 or 1 0, characterized in. The gypsum raw material powder, the α-type hemihydrate gypsum and the β-type hemihydrate gypsum and a mass ratio of 50: 50 to 0: semiconductor manufacturing as claimed in claim 1 1, characterized in that is a mixture of 100 A method for manufacturing a device member.

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