Plasma treatment equipment components

Abstract

To provide a member for plasma processing equipment having a high breakdown voltage.SOLUTION: A member for plasma treatment equipment comprises an aluminum base material and an oxide film formed on the aluminum base material and having a porous structure. The oxide film has a first oxide film formed on a surface of the aluminum base material, a second oxide film formed on a side opposite to the aluminum base material side of the first oxide film, and a third oxide film formed on a side opposite to the first oxide film side of the second oxide film. The first oxide film is harder than the second oxide film and the third oxide film. The first oxide film, the second oxide film, and the third oxide film have a sealed hole formed in each of the films. The first oxide film has a barrier layer at a part contacting the aluminum base material, and the barrier layer has a thickness of 80 nm to 210 nm.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a member for a plasma processing apparatus used in a plasma processing apparatus. [Background technology]

[0002] Conventionally, as a member used in a plasma processing apparatus, a member for a plasma processing apparatus in which an oxide film is formed on an aluminum base material and a thermal sprayed film is formed on the oxide film has been known (see, for example, Patent Documents 1 and 2). As described above, by providing a thermal sprayed film on the oxide film, the plasma resistance of the member for a plasma processing apparatus is improved.

[0003] Patent Document 1 discloses a multi-layered member in a vacuum processing apparatus that processes a substrate to be processed based on a plasma reaction, in which an oxide film layer is formed on the surface of an electrode body placed in a vacuum processing chamber, and an alumina sprayed film is formed on the surface of this oxide film layer. According to Patent Document 1, the alumina sprayed film protects the oxide film layer, preventing cracks and peeling of the oxide film layer, preventing particle generation, and extending the lifespan to reduce replacement frequency and improve the operation rate of the apparatus.

[0004] Patent Document 2 discloses an anodizing process for treating a member having an oxide coating formed on the surface of a substrate, the process including a step of immersing the substrate in an alkaline organic solvent and a step of generating a plasma discharge in the alkaline organic solvent, in a manufacturing method for an internal member of a plasma processing vessel in which a thermal spray coating is formed on the oxide coating. Examples of the internal member of the plasma processing vessel include an electrode protection member and an insulating ring. In Patent Document 2, the adhesion of the thermal spray coating to the surface of the substrate is improved by carrying out the above-mentioned process. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2000-114189 A [Patent Document 2] Patent No. 4430266 Summary of the Invention [Problem to be solved by the invention]

[0006] Incidentally, due to the recent trend toward higher energy in plasma processing steps, members for plasma processing apparatuses are required to have a higher withstand voltage.

[0007] The present invention has been made in view of the above, and has an object to provide a member for a plasma processing apparatus having a high withstand voltage. [Means for solving the problem]

[0008] In order to solve the above-mentioned problems and achieve the object, the member for a plasma processing apparatus according to the present invention comprises an aluminum base material and an oxide film having a porous structure formed on the aluminum base material, the oxide film having a first oxide film formed on a surface of the aluminum base material, a second oxide film formed on a side of the first oxide film opposite to the aluminum base material side, and a third oxide film formed on a side of the second oxide film opposite to the first oxide film side, the first oxide film being harder than the second oxide film and the third oxide film, and the first oxide film, the second oxide film, and the third oxide film are characterized in that pores formed in each film are sealed.

[0009] In addition, the member for a plasma processing apparatus according to the present invention is characterized in that, in the above-mentioned invention, it further comprises a ceramic sprayed film formed on the side of the oxide film opposite to the aluminum base.

[0010] In the plasma processing apparatus member according to the present invention, in the above-mentioned invention, the second oxide film becomes harder from the third oxide film side toward the first oxide film side.

[0011] Moreover, in the above-mentioned invention, the member for a plasma processing apparatus according to the present invention is characterized in that the oxide film has a porosity of 1% or more and 2% or less.

[0012] In addition, in the above-mentioned invention, the member for a plasma processing apparatus according to the present invention is characterized in that the first oxide film has a barrier layer in a portion in contact with the aluminum base, and the barrier layer has a thickness of 80 nm or more and 210 nm or less.

[0013] In addition, in the member for a plasma processing apparatus according to the present invention, in the above-mentioned invention, the oxide film is sealed with alumina hydrate, and the alumina hydrate has a molecular weight of 1.4 or more and 2 or less.

[0014] In addition, in the above-mentioned plasma processing apparatus member according to the present invention, the oxide film has a thickness of 70 μm or more and 130 μm or less. Effect of the Invention

[0015] The present invention has an effect of realizing a member for a plasma processing apparatus having a high withstand voltage. [Brief description of the drawings]

[0016] [Figure 1] FIG. 1 is a cross-sectional view showing a structure of a member for a plasma processing apparatus according to one embodiment of the present invention. [Diagram 2] FIG. 2 is an enlarged cross-sectional view of a part of the member for the plasma processing apparatus shown in FIG. [Diagram 3] FIG. 3 is a microscope image showing an example of an oxide film in a member for a plasma processing apparatus according to one embodiment of the present invention, and is a microscope image showing a cross section of the oxide film. [Figure 4] FIG. 4 is an SEM image showing an example of an oxide film in a member for a plasma processing apparatus according to one embodiment of the present invention, and is an SEM image showing a cross section of the oxide film. [Diagram 5]FIG. 5 is an SEM image showing an example of an oxide film in a member for a plasma processing apparatus according to one embodiment of the present invention, and is an SEM image showing a cross section of the oxide film. [Figure 6] FIG. 6 is a diagram showing physical properties of the member for a plasma processing apparatus according to one embodiment of the present invention and a member for a plasma processing apparatus according to a comparative example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, the embodiments of the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the following embodiments. Also, each drawing referred to in the following description merely shows the shape, size, and positional relationship in a schematic manner to the extent that the contents of the present invention can be understood. In other words, the present invention is not limited to only the shape, size, and positional relationship exemplified in each drawing.

[0018] Fig. 1 is a cross-sectional view showing the structure of a member for a plasma processing apparatus according to one embodiment of the present invention. Fig. 2 is an enlarged cross-sectional view of a part (region R) of the member for a plasma processing apparatus shown in Fig. 1. The member for a plasma processing apparatus 1 shown in Fig. 1 includes a base material 10 which is an insulating substrate, an oxide film 20 formed on a part of the surface of the base material 10, and a thermal spray film 30 provided on the side of the oxide film 20 opposite to the base material 10 side. The member for a plasma processing apparatus 1 is used as a material for members used in plasma processing apparatuses, such as electrodes and electrode protection members, and the member is constructed by processing a base material consisting of the base material 10, the oxide film 20, and the thermal spray film 30.

[0019] The substrate 10 is an aluminum substrate formed using aluminum, an alloy containing aluminum as a main component, or an aluminum oxide. The thermally sprayed film 30 is a ceramic thermally sprayed film formed using ceramic.

[0020] Fig. 3 is a microscope image showing an example of an oxide film in a member for a plasma processing apparatus according to an embodiment of the present invention, which is a microscope image showing a cross section of the oxide film. Figs. 4 and 5 are scanning electron microscope (SEM) images showing an example of an oxide film in a member for a plasma processing apparatus according to an embodiment of the present invention, which are SEM images showing a cross section of the oxide film. Figs. 3 to 5 show regions (films) corresponding to the respective portions of the oxide film shown in Fig. 2.

[0021] The oxide film 20 is an alumina film formed of anodized aluminum and has a three-layer structure. The oxide film 20 is composed of a first oxide film 21 formed on the surface of the substrate 10, a second oxide film 22 laminated on the side of the first oxide film 21 opposite to the substrate 10 side, and a third oxide film 23 laminated on the side of the second oxide film 22 opposite to the first oxide film 21 side (see, for example, FIGS. 2 and 3).

[0022] The first oxide film 21 has a higher hardness than the second oxide film 22. The second oxide film 22 has a higher hardness than the third oxide film 23. That is, the hardness of the oxide film 20 decreases from the substrate 10 side to the thermal spray film 30 side. The hardness of the first oxide film 21 is preferably 400 Hv or more and 430 Hv or less. The hardness of the second oxide film 22 is preferably 200 Hv or more and 380 Hv or less. The hardness of the third oxide film 23 is preferably 40 Hv or more and 80 Hv or less. The hardness of the second oxide film 22 increases from the third oxide film 23 side to the first oxide film 21 side. If the hardness of the first oxide film 21 is less than 400 Hv, the abrasion resistance may decrease, and the withstand voltage may decrease. If the hardness of the first oxide film 21 is more than 430 HV, cracks may occur in the film.

[0023] Of the first oxide film 21, the second oxide film 22 and the third oxide film 23, the second oxide film 22 is the largest in length (thickness) in the stacking direction, and the first oxide film 21 is the smallest. Specifically, the first oxide film 21 is 80 nm or more and 210 nm or less. The second oxide film 22 is preferably 60 μm or more and 100 μm or less. The third oxide film 23 is 20 μm or more and 30 μm or less. The thickness of the oxide film 20 is preferably 70 μm or more and 130 μm or less, and particularly preferably 70 μm or more and 120 μm or less.

[0024] The first oxide film 21 has a film layer 21a formed on the second oxide film 22 side and a barrier layer 21b formed on the substrate 10 side. The barrier layer 21b is a non-conductive film formed on the substrate surface, and supports the growth of the film (film layer 21a) during film formation. The barrier layer 21b preferably has a thickness of 80 nm or more and 210 nm or less. In this case, the barrier layer 21b has a higher content in the first oxide film 21 than the film layer 21a. Note that a conventional barrier layer has a thickness of 30 nm to 40 nm in a film similar to that of the first oxide film 21. The film layer 21a and the barrier layer 21b have the same hardness, and preferably have the above-mentioned hardness (400 Hv or more and 430 Hv or less).

[0025] The oxide film 20 has a porosity of 1% or more and 2% or less. In the oxide film 20, the first oxide film 21, the second oxide film 22, and the third oxide film 23 are porous films, and the pores of each film are filled with alumina hydrate. This alumina hydrate is preferably a hydrate having a molecular weight of 1.4 or more and 2.0 or less. In the first oxide film 21, the above-mentioned pores are formed in the film layer 21a.

[0026] Next, a method for producing the member 1 for a plasma processing apparatus will be described. First, the above-mentioned substrate 10 is prepared. The oxide film 20 is formed on the substrate 10. When forming the oxide film 20, the third oxide film 23 is formed first. Then, the second oxide film 22 is formed. After the second oxide film 22 and the third oxide film 23 are formed, the first oxide film 21 is formed. At this time, a film layer (film layer 21a and barrier layer 21b) is formed on the first oxide film 21 by anodizing treatment. Then, alumina hydrate is filled into the holes formed in the film. In this manner, the oxide film 20 is formed on the substrate 10. Then, a thermal spray film 30 is formed on the side of the oxide film 20 opposite to the substrate 10 side.

[0027] The physical properties of the plasma processing apparatus member 1 (Example) having the three-layer oxide film produced as described above and the plasma processing apparatus member having a single-layer oxide film (Comparative Example) will be described with reference to Fig. 6. Fig. 6 is a diagram showing the physical properties of the plasma processing apparatus member according to one embodiment of the present invention and the plasma processing apparatus member according to the Comparative Example. In Fig. 6, the pore size is the average value of the diameter of the pores, and the pore number is the number of pores in the pores.

[0028] As shown in FIG. 6, it is understood that the member 1 for a plasma processing apparatus according to the example has a higher withstand voltage both before and after heating, as compared with the member for a plasma processing apparatus according to the comparative example. Moreover, the porosity of the member 1 for a plasma processing apparatus according to the example is lower than the porosity of the member for a plasma processing apparatus according to the comparative example, and falls within the above-mentioned range.

[0029] According to the above-described embodiment, the oxide film 20 formed between the substrate 10 and the thermal sprayed film 30 has a three-layer structure consisting of the first oxide film 21, the second oxide film 22 and the third oxide film 23, and the first oxide film 21 on the substrate 10 side is made harder than the other films (the second oxide film 22 and the third oxide film 23), thereby making it possible to obtain a member for a plasma processing apparatus having a high withstand voltage.

[0030] In this manner, the present invention may include various embodiments not described here, and various design modifications may be made without departing from the technical idea defined by the claims.

[0031] In the above-described embodiment, the plasma processing apparatus member 1 having the thermal sprayed film 30 formed on the oxide film 20 has been described as an example. However, the plasma processing apparatus member may have a configuration not having the thermal sprayed film 30, that is, may be composed of the substrate 10 and the oxide film 20.

[0032] As described above, the member for a plasma processing apparatus according to the present invention is suitable for realizing a member for a plasma processing apparatus having a high withstand voltage. [Explanation of symbols]

[0033] 1 Plasma treatment equipment components 10 Base material 20 Oxide film 21 First oxide film 21a Coating layer 21b Barrier layer 22 Second oxide film 23 Third oxide film 30 Thermal spray coating

Claims

1. An aluminum substrate; An oxide film having a porous structure provided on the aluminum base material and formed of anodized aluminum; Equipped with The oxide film is a first oxide film formed on a surface of the aluminum base material and having a hardness of 400 Hv or more and 430 Hv or less; a second oxide film formed on a side of the first oxide film opposite to the aluminum substrate; a third oxide film formed on a side of the second oxide film opposite to the first oxide film side; It has a three-layer structure consisting of the second oxide film has a thickness larger than those of the first oxide film and the third oxide film, the first oxide film is harder than the second oxide film and the third oxide film; the second oxide film becomes harder from the third oxide film side toward the first oxide film side, pores formed in each of the first oxide film, the second oxide film, and the third oxide film are sealed with alumina hydrate; the first oxide film has a non-conductive barrier layer in a portion in contact with the aluminum base material, The barrier layer has a thickness of 80 nm or more and 210 nm or less. A member for a plasma processing apparatus comprising:

2. a ceramic sprayed film formed on the side of the oxide film opposite to the aluminum substrate; The member for a plasma processing apparatus according to claim 1 , further comprising:

3. The oxide film has a porosity of 1% or more and 2% or less.

3. The member for a plasma processing apparatus according to claim 1 or 2.

4. The alumina hydrate has a hydrate content of 1.4 to 2.

4. The member for a plasma processing apparatus according to claim 1, wherein the member is a metal.

5. The oxide film has a thickness of 70 μm or more and 130 μm or less, Within the range of the oxide film thickness, The first oxide film has a thickness of 80 nm or more and 210 nm or less, The second oxide film has a thickness of 60 μm or more and 100 μm or less, The third oxide film has a thickness of 20 μm or more and 30 μm or less.

5. The member for a plasma processing apparatus according to claim 1, wherein the member is a metal.

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