JPH08193295A - Vacuum chamber member made of aluminum of aluminum alloy - Google Patents

Abstract

PURPOSE: To provide a vacuum chamber member to be used in the CVD device, PVD device, dry etching device, etc., made of Al or Al alloy and exhibiting excellent corrosion resistance to the corrosive gas and plasma to be introduced into a vacuum chamber. CONSTITUTION: This vacuum chamber member made of Al or Al alloy has an anodic oxide film consisting of a porous layer 4 having many pores 3 exposed to the surface and a barrier layer 5 free of pores, the pore diameter of the porous layer 4 is decreased on the surface side and increased on the substrate 1 side. The anodic oxide film thus constituted may have a part in an optional zone in the depth direction wherein the pore diameter of the porous layer 4 is continuously changed or a part wherein the pore diameter is discontinuously changed. Further, the anodic oxide film can have a part in the optional zone in the depth direction wherein the pore diameter is not changed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum chamber member made of Al or Al alloy used in a CVD apparatus, a PVD apparatus, a dry etching apparatus, etc., and is suitable for corrosive gas or plasma introduced into the vacuum chamber. On the other hand, the present invention relates to a vacuum chamber member made of Al or Al alloy that exhibits excellent corrosion resistance.

[0002]

2. Description of the Related Art Since a corrosive gas containing a halogen element such as Cl or F is introduced as a reaction gas or an etching gas into a vacuum chamber used in a CVD apparatus, a PVD apparatus, a dry etching apparatus or the like. Corrosion resistance to corrosive gas (hereinafter referred to as gas corrosion resistance) is required. In the case of a thermal plasma CVD device, etc.,
In addition to the above corrosive gas, halogen-based plasma is also generated, and therefore corrosion resistance to plasma (hereinafter referred to as plasma resistance) is also important.

Therefore, stainless steel has been mainly used as the material for the vacuum chamber. However, the vacuum chamber made of stainless steel has a problem that it is heavy and requires a large amount of work on the base, and the thermal conductivity is not sufficient, and it takes a long time to bake at the time of operation. Further, heavy metals such as Cr, which is an alloy component of stainless steel, may be released during the process as a pollution source for some reason. Therefore, development of a vacuum chamber made of Al or Al alloy, which is lighter than stainless steel, excellent in thermal conductivity, and free from the risk of heavy metal contamination, is under study.

However, the surface of a bare metal of Al or Al alloy is not necessarily good in gas corrosion resistance and plasma resistance, and it is considered necessary to perform some kind of surface treatment, and various studies have been conducted. For example, Japanese Patent Publication No. 5-538
Japanese Patent Laid-Open No. 70-70 discloses an invention in which the surface of an Al or Al alloy vacuum chamber member is anodized to form an anodized film to improve the gas corrosion resistance of Al or Al alloy to form a vacuum chamber member. Is disclosed.
However, the anodized film does not cause any reaction with the corrosive gas or plasma,
When it is corroded during use, reaction products are generated as fine particles, and when it is used in, for example, semiconductor manufacturing, it may cause defective products, and improvement has been desired.

Japanese Patent Publication No. 5-53871 discloses a technique for forming a film (for example, TiN, TiC, etc.) having excellent corrosion resistance on the surface of a vacuum chamber member made of Al or Al alloy by using an ion plating method. Is disclosed. However, if the above-mentioned film is formed by a vapor phase synthesis method such as ion plating, there is a problem that a considerable processing cost is required.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and is based on the premise that a cost-effective anodic oxidation treatment method is adopted, the gas corrosion resistance and the plasma resistance. The present invention is intended to provide a vacuum chamber member made of Al or Al alloy excellent in heat resistance.

[0007]

The vacuum chamber member made of Al or Al alloy according to the present invention which achieves the above object,
The gist of the present invention is to have an anodic oxide film composed of a porous layer having a large number of pores opened on the surface and a barrier layer having no pores, and to make the pore diameter of the porous layer small on the surface side and large on the substrate side. It is a thing.

The anodic oxide film, which has a small pore diameter on the surface side and a large pore diameter on the substrate side, has a continuous change portion in the pore area of the porous layer in an arbitrary section in the depth direction. It may have a discontinuous change portion. Further, the pore diameter of the porous layer may have a non-change portion in an arbitrary section in the depth direction. further,
By incorporating two or more kinds of elements selected from the group consisting of C, S, N, P, F and B in the anodic oxide film, more excellent corrosion resistance can be obtained.

The Al alloy base material used for the vacuum chamber member has an average grain size of crystallized substances and precipitates of 10 μm.
Or by using an Al alloy material adjusted such that the above-mentioned crystallized substances and precipitates are arranged in parallel to the member surface having the largest area in the member surface. In addition to corrosion resistance, the corrosion resistance of the base material itself can be expected. Further, it is preferable that the average grain size of the crystallized substances and the precipitates is 10 μm or less, and the arrangement direction of the crystallized substances and the precipitates is parallel to the surface of the member having the maximum area.

In the present invention, the vacuum chamber member means not only the structural material of the vacuum chamber, but also the gas diffusion plate (GDP), clamper,
The present invention is applied to all members such as shower heads, susceptors, clamp rings, electrostatic chucks, etc. made of Al alloy, and in the following description, all of these members are collectively referred to as vacuum chamber members. . However, in a chamber to be actually manufactured, not all of its members have to be configured by the improved product of the present invention, but other improved Al alloys, conventionally known stainless steel, ceramics / plastic composite materials In some cases, it may be manufactured in combination with the above.

[0011]

Since the vacuum chamber member made of Al or Al alloy has poor corrosion resistance to the above-mentioned corrosive gas and plasma, the inventors of the present invention have conducted extensive studies on various surface modification techniques in order to improve it. . As a result, Al or A
When performing anodizing treatment on a vacuum chamber member made of l-alloy, it is possible to control the internal structure and composition of the anodized film, which greatly improves gas corrosion resistance and plasma resistance. We have found that excellent results can be obtained.

Prior art (for example, the above Japanese Patent Publication No. 5-5
Japanese Patent No. 3870) also includes a technique for controlling the film thickness of the anodized film when performing anodizing treatment. It is also known that the structure of the anodic oxide film changes by changing the electrolysis conditions. However, no attempt has been made to suppress the corrosion reaction with corrosive gas or plasma by controlling the internal structure and composition of the anodized film, and there are no reports of cases examined from this viewpoint. Absent.

FIG. 1 shows Al or Al formed by anodizing treatment.
It is a partial cross section explanatory drawing which shows notionally the schematic structure of the anodized film formed on the surface of the alloy vacuum chamber member. The anodized film grows the cell 2 having the pore 3 at the center position in the depth direction while starting the electrolysis and perforating the concave portion called the pore 3 in the base material 1.

FIG. 2 is a cross-sectional view of the anodized film. In the present invention, the portion in which the pores 3 are formed is a porous layer 4, and a layer having no pores is interposed between the porous layer 4 and the substrate 1. Is called a barrier layer 5. Since the barrier layer 5 does not have gas permeability, it prevents gas or plasma from coming into contact with Al or Al alloy.

In the case of an anodic oxide film having a porous layer and a barrier layer as described above, the pore diameter of the porous layer, the cell diameter and the thickness of the barrier layer have a positive correlation. I know that. Therefore, when the present inventors first investigated the relationship between the internal structure of the anodized film and the gas corrosion resistance and plasma resistance, the following findings were obtained.

First, it was found that the smaller the pore diameter and the cell diameter on the surface of the porous layer, the better the plasma resistance. This is because the smaller the opening area of the pores, the more uniform the surface of the porous layer is, so that when the pore diameter and the cell diameter are large, the local concentration of plasma that tends to occur at the side edge of the pore surface is suppressed. It is considered that it is possible to suppress the nonuniform plasma concentration near the surface of the porous layer.

Secondly, it has been found that the internal structure of the porous layer on the substrate side has a large pore diameter and a large cell diameter, which effectively acts to improve the gas corrosion resistance. The reason is that the substantial surface area including the surface area inside the pore is reduced by making the structure with a large pore diameter and cell diameter, and the area that can react with the corrosive gas is reduced, so that the volume change due to the reaction product It is thought that this is because the adverse effect on the internal structure is reduced.

Thirdly, it was found that the thicker the barrier layer, the better the gas corrosion resistance. As mentioned above, due to the presence of the barrier layer, the corrosive gas cannot easily contact the Al or Al alloy substrate. However, if it is left in a corrosive gas atmosphere for a long time, it may gradually penetrate into the barrier layer depending on the type of gas. Therefore, it is desirable that the barrier layer be thicker in order not only to shield from corrosive gas but also to exhibit excellent gas corrosion resistance even when exposed to corrosive gas for a long time.

From the above findings, it is concluded that it is desirable to form a structure in which the pore size on the surface side of the porous layer is formed as small as possible, while the pore size on the substrate side is formed as large as possible to thicken the barrier layer. Obtained.

However, the present invention does not limit the pore diameter, and at least improves the corrosion resistance by increasing the pore diameter on the substrate side of the porous layer to be larger than the pore diameter on the surface side. In order to obtain the property, the surface-side pore diameter is preferably 80 nm or less, more preferably 50 nm or less, further preferably 30 nm or less. In addition, the thickness of the barrier layer is preferably 50 nm or more, more preferably 80 nm or more, in order to sufficiently exhibit the gas corrosion resistance.

Further, in the present invention, it is sufficient that at least the pore diameter of the porous layer on the base material side is larger than the pore diameter of the front surface side, and the pore diameter in the intermediate portion between the base material side and the surface side of the pores of the porous layer is set to It is not limited. Therefore, the middle part is a continuous change part, a discontinuous change part,
The non-changed portions can be arbitrarily mixed, and the pore diameter may be once reduced on the way from the base material side to the surface side, or may include a portion interrupted on the way.

For example, the pore diameter may be continuously changed in the depth direction. In this case, the pore diameter gradually increases from the front surface side to the base material side, or the base diameter increases from the front surface side. It is possible to use various materials such that the pore diameter is gradually increased toward the material side, then the pore diameter is decreased again, and the pore diameter is increased again to continuously change the pore diameter.

Further, it may have a structure in which two or more porous layers having different pore diameters are laminated so that the pore diameter changes stepwise. In this case, it is preferable that the change in the pore diameter is as small as possible, and it is desirable to provide and stack an inclined layer as the intermediate layer in which the pore diameter continuously changes. The selection of such a structure of the porous layer may be appropriately selected depending on the application site of each member.

In the above description, the case where the internal structure represented by the pore diameter of the anodic oxide film changes in the depth direction has been described. However, when the electrolysis conditions are changed to change the pore diameter, the pore diameter of the surface is not always uniform over the entire surface, and may change in plan view depending on the shape and position of the surface. Many. Therefore, it is possible to select a portion that requires particularly high plasma resistance and make the surface-side pore diameter of that portion as small as possible. Therefore, when viewed locally, there may be a portion that does not satisfy the condition of the present invention regarding the pore diameter, but it is sufficient if the condition of the present invention is satisfied as an overall tendency.

The present invention does not limit the thickness of the anodic oxide coating, but it is 0.0 if it has excellent corrosion resistance.
The thickness is preferably 5 μm or more, more preferably 0.1 μm or more. However, if the film thickness is too thick, cracking occurs due to the influence of internal stress and the like, the surface coating becomes insufficient, and further the film peels off, so the film thickness is preferably 50 μm or less. That is, if the film thickness exceeds 50 μm, it may be difficult to relax the stress by the film itself, cracks may occur and the film may peel off, which may cause problems of defectiveness on the contrary. Is.

The present invention does not limit the kind of solution used for electrolysis, and inorganic acids such as sulfuric acid, phosphoric acid and chromic acid, or organic acids such as formic acid and oxalic acid can be used. It is recommended to use an electrolytic solution containing oxalic acid in an amount of 1 g / liter or more from the viewpoint that the temperature can be arbitrarily controlled in a wide range. For example, FIG. 3 is a graph showing the relationship between electrolysis voltage and current density when an anodized film is formed under various electrolysis conditions using three types of anodizing solutions of sulfuric acid, oxalic acid, and phosphoric acid. In the case of sulfuric acid, the film formation rate is high because the current density greatly changes due to the change in electrolysis voltage. On the other hand, in the case of phosphoric acid, the change in current density is small even when the electrolysis voltage is changed relatively large, and the film formation rate is small. Therefore, it can be said that the film formation rate of sulfuric acid is too high to control the film thickness, and that of phosphoric acid is too low and the production efficiency is poor. On the other hand, oxalic acid has a change in current density with respect to a change in electrolysis voltage that is intermediate between sulfuric acid and phosphoric acid, and it is easy to control the internal structure without degrading production efficiency as much as phosphoric acid.

The anodic oxide film having improved gas corrosion resistance and plasma resistance by controlling the internal structure of the anodic oxide film has been described above. As a result of further intensive studies by the present inventors. It was found that the corrosion resistance can be further improved by adjusting the composition of the anodized film. That is, C, S, N, P, F, B
It has been found that the corrosion resistance to gas and plasma is further improved by incorporating two or more elements selected from the group consisting of (hereinafter, sometimes referred to as an element according to the present invention) in the anodized film. is there.

If an organic acid such as oxalic acid or formic acid is used as the anodizing solution, Al ₄ C ₃ , Al ₂
Compounds containing C such as C ₆ , HCOOH and (COOH) ₂ [Other C such as —CO ₃ , —C ₂ O ₄ and —COOH
A compound containing an _x O _y H _z group (an integer of x ≧ 1, y, z ≧ 0)] is contained in the anodized film. Therefore, when an organic acid such as oxalic acid is used in the anodizing solution, one or more elements other than S, N, P, F, and B other than C may be contained to form two or more elements. As a typical method, the compounds exemplified below may be added to the anodizing treatment solution.

In case of S: H₂ SO_Four , Al₂ (SO
_Four )₃ Etc. to the anodizing treatment solution
₂ SO_Four , H₂ SO₃ , Al₂ (SO_Four )₃ , Al (H
SO _Four )₃ Compounds containing S such as [others, -SO_Four ,-
SO₃ , -HSO_Four Such as S _x O_y H_z Group (x ≧ 1,
[compound containing y, z ≧ 0)] is an anodized film
Contained in.

In the case of N: HNO ₃ , Al (NO ₃ )
By adding ₃ etc. to the anodizing solution, HNO
Compounds containing N such as ₃ , HNO ₂ and Al (NO ₃ ) ₃ [in addition, N _x O _y H _z groups such as —NO ₃ and —NO ₂ (x ≧ 1, y, integers of z ≧ 0) Compounds contained] are contained in the anodized film.

For P: H₃ PO_Four , H₃ PO₃ ,
AlPO_Four Is added to the anodizing solution.
H₃ PO_Four , H₂ PHO₃ , AlPO_Four Including P such as
Mu compound [Other, -PO_Four , -HPO_Four , -H₂ PO
_Four , -HPHO₃ Such as P_x O _y H_z Groups (x ≧ 1, y,
containing an integer of z ≧ 0] is contained in the anodized film.
Contained.

In the case of F: A compound containing F is contained in the anodized M coating film by adding HF or the like to the anodizing treatment solution. In the case of B: (NH ₄ ) ₂ B ₄ O ₇ , H ₃ BO _3, etc. were added to the anodizing solution to obtain B ₂ O ₃ ,
Compounds containing B such as (NH ₄ ) ₂ B ₄ O ₇ [others,-
BO ₃ , -B ₄ O _{7 and} other B _x O _y H _z groups (x ≧ 1, y,
containing an integer of z ≧ 0] is contained in the anodized film.

The amount of the above compound added to the anodizing solution is preferably 0.1 g / liter or more, and 0.1 g / liter in terms of the amount of each element of S, N, P, F and B.
When it is less than liter, it is difficult to exert a remarkable effect.

As described above, when oxalic acid is used as the anodizing treatment solution, a C-containing compound derived from oxalic acid is contained in the anodic oxide film, so that elements other than C (S, N, P) according to the present invention can be used. , F, B), and when sulfuric acid is used as an anodizing treatment solution, since the S-containing compound derived from sulfuric acid is contained in the anodized film, the present invention other than S can be used. Elements related to (C, N, P,
One or more of F and B) may be contained. Thus, depending on the type of element contained in the anodizing solution, a compound containing an element according to the present invention other than the contained element is added to the anodizing solution, and as a result, two or more kinds of The element according to the invention may be contained in the anodized film.

In addition to the method of adding the above compound to the anodizing treatment solution, the Al alloy of the base material containing the element according to the present invention as an alloying element may be used, or ion implantation or the like may be used. It is also possible to adopt a method in which the above elements are contained only in the surface layer of the base material by the surface modification method and then anodization is performed. Whichever method is used, the gas corrosion resistance and plasma resistance of the anodized film can be improved by finally incorporating two or more elements according to the present invention.

The amount of the above elements to be contained in the anodized film (in% by weight) is preferably 0.01% or more, and 0.5% or less in order to improve gas corrosion resistance and plasma resistance. % Or more is more desirable. S is 0.02
% Or more is preferable, and 2% or more is more preferable. N
Is preferably 0.01% or more, and more preferably 0.7 or more. P is preferably 0.015% or more, and more preferably 1% or more. F is preferably 0.01% or more, and more preferably 0.5% or more. B is 0.01
It is preferably 5% or more, and more preferably 0.3% or more.

Although the present invention does not limit the Al alloy as the base material, for example, the chamber material has a mechanical strength,
Excellent in terms of thermal conductivity, electrical conductivity and corrosion resistance 10
00 series alloys, 5000 series alloys, and 6000 series alloys are desirable. The 1000 series alloy is a pure aluminum series, but 50
In the case of a 00-based alloy, at least S is used as an alloy component.
i: 0.5 wt% or less and Mg: 0.5 to 6.0 wt% are preferable, and in the case of a 6000 series alloy, Si: 0.2 to 1.
It is preferable to contain 2% by weight and Mg: 0.4 to 1.5% by weight. In the case of chamber internal parts, 50
In addition to the 00-based alloy and the 6000-based alloy, a 2000-based alloy and a 7000-based alloy may be used. Also, Al
By containing Mg, Si, Cu, Fe, etc. as alloy components of the alloy, it is also effective in improving crack resistance of the anodic oxide film against high frequency and high temperature (thermal cycle) and reducing internal stress of the oxide film. I know. Especially 6000
The presence of Mg and Si, which are the constituent elements of the system alloy, is effective, and the effect may be affected by the final heat treatment conditions of the material.

When an Al alloy is used as a base material, it often contains crystallized substances and precipitates due to alloying elements and unavoidable impurities contained in the Al alloy. When crystallized substances and precipitates are present, halogen elements such as Cl and F, which are highly corrosive, easily enter the interface with Al that is the matrix, which may adversely affect the corrosion resistance.
Therefore, select a material in which crystallized substances and precipitates in the Al alloy are finely dispersed, or configure such that crystallized substances or precipitates do not continuously exist in the intrusion direction of the corrosive element. Is recommended. Specifically, it is preferable to use a material having an average grain size of crystallized substances and precipitates of 10 μm or less.
When the average grain size of crystallized substances and precipitates exceeds 10 μm, the arrangement direction of crystallized substances and precipitates arranged by hot working is the maximum with respect to the surface of the member, especially exposed to plasma or gas. It is desirable to use it so that it is parallel to a surface having a surface area. Further, it is more preferable to control the grain size and the arrangement direction of the crystallized substances and precipitates at the same time as described above.

The average grain size of the above-mentioned crystallized substance and precipitate is 10 μm.
The reason why the value of m or less is effective for improving the corrosion resistance is that when the crystallized substances and the precipitates are finely formed, the continuity of the crystallized substances and the precipitates is lost and the mutual spacing is also appropriate. It is considered to be easy to maintain and to improve the corrosion resistance. In the case of crystallized substances, the average particle size is preferably 6 μm or less, and more preferably 3 μm or less. In the case of precipitates, the average particle size is 2μ
It is preferably m or less, and more preferably 1 μm or less. Even if the average grain size of crystallized substances and precipitates satisfies the range of the present invention, if the crystallized substances or precipitates having the maximum grain size are too large, the corrosion resistance is adversely affected. There are cases. Therefore, the maximum grain size of crystallized substances and precipitates is preferably 15 μm or less, more preferably 10 μm or less.

Further, depending on the environment in which the member according to the present invention is used, precipitates may grow during use and the particle size thereof may increase. Even when the particle size becomes large, it is preferable that the maximum particle size is within the above range, but when it is used in an environment where it is difficult, the material with the smallest particle size of the precipitate (specifically, It is desirable to select a material having an average grain size of precipitates of 2 μm or less, preferably 1 μm or less.

Factors for finely forming crystallized substances and precipitates in the Al alloy include controlling the casting speed in addition to reducing the content of alloying elements and unavoidable impurities in the alloy composition. . That is, by increasing the cooling rate during casting as much as possible, it is possible to control the average grain size and volume fraction of crystallized substances and precipitates to be small. Specifically, the cooling rate during casting is 1 ° C
/ Sec or more is preferable, and 10 ° C / sec or more is more preferable.

Further, with respect to the precipitate, the grain size, shape, distribution state, etc. can be controlled by the final heat treatment (for example, those called T4, T6 etc.). As the method, it is possible to set the solution heat treatment temperature as high as possible (for example, to raise the temperature to the solid-phase high temperature to the utmost) to form a supersaturated solid solution, and then to perform multi-step aging treatment such as two-stage or three-stage treatment. It is valid. Even after the casting as described above, it is possible to control the grain size of the precipitate to be smaller by performing the above heat treatment.

Further, the crystallized substances and the precipitates are likely to be arranged in the extrusion direction or the rolling direction during hot extrusion or hot rolling after casting. Even when crystallized substances and precipitates are arranged in a specific direction in this way, when used as a vacuum chamber member, the arrangement direction is taken into consideration and the maximum area is provided for each shape of the vacuum chamber member. By making the planes parallel to the array direction of crystallized substances and precipitates, it contributes to the improvement of corrosion resistance.

Depending on the type of vacuum chamber member,
Due to the restrictions derived from the shape of the member, the surface having the maximum area may be perpendicular to the direction in which crystallized substances and precipitates are arranged. Examples include a susceptor having a disk-shaped member, a gas diffusion plate, a dielectric plate of an electrostatic chuck, and the like. For example, the susceptor is often manufactured in a disk shape by cutting a columnar extruded material into slices, the arranging direction of crystallized substances and precipitates arranged in the hot extrusion direction, and the top and bottom surfaces of the susceptor. Are generally orthogonal. Therefore, in the case of a vacuum chamber member such as such a susceptor, the arrangement direction of the crystallized substances and the precipitates is not taken into consideration, but rather the average grain size of the crystallized substances and the precipitates is controlled as described above. The corrosion resistance may be improved by controlling it to be small.

Furthermore, the average grain size of crystallized substances and precipitates and /
Alternatively, in addition to controlling the arrangement direction, it is possible to further improve the corrosion resistance by controlling the volume fraction of crystallized substances and precipitates to be as small as possible. Specifically, the volume fraction of crystallized substances and precipitates is recommended to be 4% or less, more preferably 2% or less, and further preferably 1% or less.

Desirable ranges of the combination of the average grain size of the crystallized substances and the precipitates and the volume fraction are as follows. That is, in the case of a crystallized substance, it is preferable that the average grain size is 6 μm or less and the volume fraction is 4% or less (desirably 2% or less), and the average grain size is 3 μm or less and the volume fraction is 2%. % Or less (desirably 1% or less) is more preferable. On the other hand, in the case of precipitates, the average particle size is preferably 2 μm or less and the volume fraction is 4% or less (desirably 2% or less), and the average particle size is 1 μm or less and the volume fraction is 2% or less. It is more preferable if it is (preferably 1% or less).

In the present invention, the crystallized substance means a compound formed from a liquid phase, and the precipitate means a compound formed from a solid phase. The types of crystallized substances and precipitates vary depending on the composition of the Al alloy and are not limited by the types, but are as follows, for example.

Crystallized substances of 1000 series Al alloys (hereinafter 10
00-based crystallized substances) include Al-Fe-based crystallized substances such as Al ₃ Fe and Al ₆ Fe, and α-AlFeSi, β-Al.
There are Al-Fe-Si based crystallized substances such as FeSi. 200
The crystallization product of the 0-system Al alloy is the same as the above-mentioned 1000-system crystallization product, and as the precipitation product, Al ₂ Cu, Al ₂ CuMg,
Al ₆ CuMg _{4 and the} like can be mentioned.

Crystallized substances of 3000 series Al alloy are 100 above.
In addition to 0-based crystallized substances, Al ₆ Mn, Al ₄ Mn, AlM
n, Al ₁₂ Mn, Al ₁₂ Fe ₃ Si, Al ₁₂ Mn ₃ S
i, Al ₉ Mn ₂ Si, etc., and the precipitates are mainly Al
₆ Mn.

The crystallized substances of 5000 series Al alloy are 100 above.
In addition to the 0-system crystallized product, Al ₃ Mg ₂ , Al ₁₂ Mg ₁₇ , A
l ₇ Cr, Al ₁₈ Mg There are _{3 Cr 2, Al 18 Mg 3} Mn 2 and the like, as the deposit Al ₃ Mg _2, Al ₂ CuMg
Etc.

The crystallization product of the 6000 series Al alloy is 100 above.
In addition to 0-type crystallized substances, Mg ₂ Si, Si, Al ₈ Mg ₅
Etc., and the precipitates are mainly Mg ₂ Si, Al ₂
There are CuMg and the like.

The crystallization product of 7000 series Al alloy is 100 above.
In addition to 0-type crystallized substances, Al ₈ Mg ₅ , AlZn, Mg ₂
Zn ₁₁ , MgZn _2, etc., and Mg ₂ Z as a precipitate
n ₁₁ , MgZn ₂ , Al ₂ Mg ₃ Zn ₃ , Al ₂ CuM
g etc.

The present invention will be described in more detail with reference to the following examples, but the following examples are not intended to limit the present invention, and any change in the design of the present invention can be made without departing from the spirit of the preceding and the following. It is included in the technical scope.

[0054]

Example 1 Using various Al alloy plates shown in Table 1, anodized films having various structures shown in Table 1 were formed to obtain test pieces. It should be noted that the pore diameters of all the porous layers continuously change in the depth direction. Table 1 shows the number of porous layers, the pore diameters on the surface side and substrate side of each porous layer, the type of electrolytic solution used for anodizing treatment, and the thickness of the anodized film.

For the purpose of evaluating the corrosion resistance of the above-mentioned test piece to a halogen-based gas, a gas corrosion test was carried out with a 5% Cl ₂ -Ar mixed gas at 300 ° C. for 4 hours,
The appearance after the test was examined and evaluated according to the following criteria. [Gas corrosion test] ○: No corrosion occurred △: Corrosion occurrence area ratio less than 5% ×: Corrosion occurrence area ratio 5% or more

Further, in order to evaluate the plasma resistance of the test piece, a chlorine plasma irradiation test was performed for 90 minutes under a low bias condition, and the etching amount was measured, and evaluated as follows. [Plasma irradiation test] ○: Etching amount less than 2 μm Δ: Etching amount 2 μm or more and less than 5 μm ×: Etching amount 5 μm or more The results of the above gas corrosion test and plasma irradiation test are shown in Table 1.
Shown in

[0057]

[Table 1]

As is clear from the results shown in Table 1, No. 1 which satisfies the conditions according to the present invention. Nos. 1 to 5 showed excellent gas corrosion resistance and plasma resistance. On the other hand, No. 6 to 9 are comparative examples that do not satisfy any of the conditions according to the present invention,
At least one of gas corrosion resistance and plasma resistance is insufficient.

Example 2 Using an oxalic acid solution as an electrolytic solution and various Al alloy plates shown in Table 2, anodic oxide coatings having various structures shown in Table 2 were formed to obtain test pieces. It should be noted that the pore diameters of all the porous layers continuously change in the depth direction. Table 2 shows the number of porous layers, the pore diameters on the surface side and the substrate side of each porous layer, and the thickness of the anodized film. Using the above test piece, a gas corrosion test and a plasma irradiation test were conducted in the same manner as in Example 1 to examine gas corrosion resistance and plasma resistance. The results are shown in Table 2.

[0060]

[Table 2]

As is clear from the results shown in Table 2, No. 1 which satisfies the conditions according to the present invention. Nos. 1 to 5 showed excellent gas corrosion resistance and plasma resistance. On the other hand, No. 6 to 9 are comparative examples that do not satisfy any of the conditions according to the present invention,
At least one of gas corrosion resistance and plasma resistance is insufficient.

Example 3 Using various Al alloy plates shown in Table 3, anodic oxide coatings having various structures shown in Table 3 were formed into test pieces. In addition, the pore diameter of the anodized film in which two or more porous layers are laminated is changed stepwise. However, No. Four
Was provided with an inclined layer having a continuously changing pore diameter as an intermediate layer. Table 3 shows the structure of the porous layer, the type of electrolytic solution used for the anodizing treatment, and the thickness of the anodized film. Using the above test piece, a gas corrosion test and a plasma irradiation test were conducted in the same manner as in Example 1 to examine gas corrosion resistance and plasma resistance. The results are shown in Table 3.

[0063]

[Table 3]

As is clear from the results shown in Table 3, No. 1 satisfying the conditions according to the present invention. Nos. 1 to 8 showed excellent gas corrosion resistance and plasma resistance. On the other hand, No. 9 to 12
It is a comparative example that does not satisfy any of the conditions according to the present invention, and at least one of gas corrosion resistance and plasma resistance is insufficient.

Example 4 Using an oxalic acid solution as an electrolytic solution and using various Al alloy plates shown in Table 4, anodic oxide films having various structures shown in Table 4 were formed to obtain test pieces. In addition, the pore diameter of the anodized film in which two or more porous layers are laminated is changed stepwise. However, No. 2 and No. In No. 8, an inclined layer having a continuously changing pore diameter was provided as an intermediate layer. Table 4 shows the structure of the porous layer and the thickness of the anodized film.

Using the above test piece, the gas corrosion test and the gas corrosion test were carried out in the same manner as in Example 1 except that the conditions of the gas corrosion test were 300 ° C. for 4 hours and the irradiation time of the chlorine plasma irradiation test was 120 minutes. A plasma irradiation test was conducted to examine gas corrosion resistance and plasma resistance. The results are shown in Table 4.

[0067]

[Table 4]

As is clear from the results shown in Table 4, No. 1 satisfying the conditions according to the present invention. Nos. 1 to 9 showed excellent gas corrosion resistance and plasma resistance. On the other hand, No. 10-14
Is a comparative example that does not satisfy any of the conditions according to the present invention, and at least one of gas corrosion resistance and plasma resistance is insufficient.

Example 5 Using various Al alloy plates shown in Table 5, anodic oxide coatings having various structures shown in Table 5 were formed into test pieces. In addition, the change in the structure of the porous layer is represented by the pore diameter, and the type of electrolyte used for the anodizing treatment and the thickness of the anodized film are shown in Table 5. Using the above test piece, a gas corrosion test and a plasma irradiation test were conducted in the same manner as in Example 1 to examine gas corrosion resistance and plasma resistance. The results are shown in Table 5.

[0070]

[Table 5]

Inventive Example No. 1 to 5 has 2 porous layers
More than one layer is laminated, and the pore diameter of each porous layer continuously changes. As is clear from the results in Table 5,
All showed excellent gas corrosion resistance and plasma resistance. On the other hand, No. Nos. 6 to 8 are comparative examples that do not satisfy any of the conditions according to the present invention, and at least one of gas corrosion resistance and plasma resistance is insufficient.

Example 6 Using an oxalic acid solution as an electrolytic solution and using various Al alloy plates shown in Table 6, anodic oxide films having various structures shown in Table 6 were formed to obtain test pieces. The changes in the structure of the porous layer are represented by the pore diameter, and the thickness of the anodized film is shown in Table 6. Using the above test piece, a gas corrosion test and a plasma irradiation test were performed in the same manner as in Example 4 to examine gas corrosion resistance and plasma resistance. The results are shown in Table 6.

[0073]

[Table 6]

Inventive Example No. 1 to 5 has 2 porous layers
More than one layer is laminated, and the pore diameter of each porous layer continuously changes. As is clear from the results in Table 6, all exhibited excellent gas corrosion resistance and plasma resistance. On the other hand, No. Nos. 6 to 9 are comparative examples which do not satisfy any of the conditions according to the present invention, and at least one of gas corrosion resistance and plasma resistance is insufficient.

Example 7 Using various Al alloy plates shown in Table 7, anodic oxide coatings having various structures shown in Table 7 were formed into test pieces. The number of porous layers as the structure of the anodized film,
Table 7 shows the pore diameters on the surface side and the base material side of each porous layer, the type of electrolytic solution used for the anodizing treatment, and the thickness of the anodized film.

For the purpose of evaluating the corrosion resistance of the above-mentioned test piece to halogen-based gas, a gas corrosion test was carried out with a 10% Cl ₂ -Ar mixed gas at 350 ° C. for 4 hours, and the appearance after the test was examined. It evaluated by the standard of. [Gas Corrosion Test] ◎: No corrosion occurrence ○: Corrosion occurrence area ratio less than 5% △: Corrosion occurrence area ratio 5% or more and less than 10% ×: Corrosion occurrence area ratio 10% or more

Further, in order to evaluate the plasma resistance of the test piece, a chlorine plasma irradiation test was performed for 120 minutes under a low bias condition, and the amount of etching was measured, and evaluated as follows. [Plasma irradiation test] ◎: Etching amount less than 1.5 μm ○: Etching amount 1.5 μm or more and less than 2 μm Δ: Etching amount 2 μm or more and less than 5 μm ×: Etching amount 5 μm or more of the above gas corrosion test and plasma irradiation test The results are shown in Table 7.
Shown in

[0078]

[Table 7]

As is clear from the results shown in Table 7, No. 1 which satisfies the conditions according to the present invention. Nos. 1 to 9 showed excellent gas corrosion resistance and plasma resistance. On the other hand, No. 10-13
Is a comparative example that does not satisfy any of the conditions according to the present invention, and at least one of gas corrosion resistance and plasma resistance is insufficient.

Example 8 Using various Al alloy plates shown in Table 8, anodic oxide coatings having various structures shown in Table 8 were formed into test pieces. The change in structure of the anodized film is represented by the pore diameter, and Table 8 shows the type of electrolyte used for the anodizing treatment and the thickness of the anodized film.

Using the above test piece, the gas corrosion test and the gas corrosion test were conducted in the same manner as in Example 7 except that the conditions of the gas corrosion test were 350 ° C. for 5 hours and the irradiation time of the chlorine plasma irradiation test was 150 minutes. A plasma irradiation test was conducted to examine gas corrosion resistance and plasma resistance. The results are shown in Table 8.

[0082]

[Table 8]

As is clear from the results shown in Table 8, No. 1 satisfying the conditions according to the present invention. Nos. 1 to 7 showed excellent gas corrosion resistance and plasma resistance. On the other hand, No. 8-11 are
It is a comparative example that does not satisfy any of the conditions according to the present invention, and at least one of gas corrosion resistance and plasma resistance is insufficient.

Example 9 Using various Al alloy plates shown in Table 9, anodic oxide films having various structures shown in Table 9 were formed into test pieces. The change in the structure of the anodized film is represented by the pore size, and Table 9 shows the type of electrolyte used for the anodizing treatment and the thickness of the anodized film.

Using the above test piece, the gas corrosion test and the gas corrosion test were conducted in the same manner as in Example 7 except that the conditions of the gas corrosion test were 370 ° C. for 5 hours and the irradiation time of the chlorine plasma irradiation test was 180 minutes. A plasma irradiation test was conducted to examine gas corrosion resistance and plasma resistance. The results are shown in Table 9.

[0086]

[Table 9]

As is clear from the results shown in Table 9, No. 1 which satisfies the conditions according to the present invention. Nos. 1 to 6 showed excellent gas corrosion resistance and plasma resistance. On the other hand, No. 7 to 9 are comparative examples that do not satisfy any of the conditions according to the present invention,
At least one of gas corrosion resistance and plasma resistance is insufficient.

Example 10 Various Al alloy plates shown in Table 10 were used to prepare test pieces. Various Al alloys are in the composition range specified in JIS standard,
It was melted in the air and cast at a solidification rate of 1 ° C / sec. After that, homogenization annealing was performed at 480 ° C. for 4 hours, and then hot rolling or extrusion was performed. The processing temperature is 450 ° C for both rolling and extrusion, the rolling reduction is 80%,
The extrusion ratio of the extrusion process was 4.

From the cross section of the material structure, a scanning electron microscope (SE
M) was used to determine the average particle size of crystallized substances and precipitates. In addition, for some test pieces, the volume fraction was calculated by image analysis processing. Table 10 also shows the average particle size and volume fraction of crystallized substances and precipitates, and the arrangement direction thereof.
The arrangement direction is the arrangement direction with respect to the surface of the maximum area where the gas corrosion resistance evaluation test and the plasma resistance evaluation test described below were performed on the test piece.

Gas Corrosion Resistance For the purpose of evaluating the gas corrosion resistance of the above-mentioned test piece against a halogen-based gas, a gas corrosion test was conducted at 400 ° C. for 2 hours with a 5% Cl ₂ —Ar mixed gas, and the appearance was evaluated. The condition was examined and evaluated according to the following criteria. ◎: No corrosion occurrence ○: Corrosion occurrence Area ratio less than 10% △: Corrosion occurrence Area ratio 10% or more and less than 20% ×: Corrosion occurrence Area ratio 20% or more Plasma resistance To evaluate the plasma resistance of the test piece, Under a low bias condition, chlorine plasma irradiation for 15 minutes was repeated 6 times at intervals of 5 minutes to perform a plasma irradiation test, and the same criteria as the gas corrosion resistance were evaluated. The results of the above gas corrosion test and plasma irradiation test are shown in Table 10.

[0091]

[Table 10]

As is clear from the results shown in Table 10, Nos. 1 to 16 satisfying the conditions according to the present invention showed excellent gas corrosion resistance and plasma resistance. Meanwhile, No. 17-27
Is a comparative example that does not satisfy any of the conditions according to the present invention, and at least one of gas corrosion resistance and plasma resistance is insufficient.

[0093]

As described above, the present invention can provide an Al or Al alloy vacuum chamber member having excellent gas corrosion resistance and plasma resistance.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional explanatory view showing a schematic structure of an anodized film.

FIG. 2 is an explanatory cross-sectional view of an anodized film having a porous layer and a barrier layer.

FIG. 3 is a graph showing the relationship between the electrolysis voltage and the current density of three kinds of anodizing treatment solutions.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kouki Ikeda 1-5-5 Takatsukadai, Nishi-ku, Kobe-shi, Hyogo Kobe Steel Works, Ltd. Kobe Research Institute

Claims (7)

[Claims] 1. An anodized film comprising a porous layer having a large number of pores open on the surface and a barrier layer having no pores, wherein the pore diameter of the porous layer is small on the surface side and large on the substrate side. A vacuum chamber member made of Al or Al alloy, characterized in that 2. The vacuum chamber member made of Al or Al alloy according to claim 1, wherein the pore diameter of the porous layer has a continuously changing portion in an arbitrary section in the depth direction. 3. The vacuum chamber member made of Al or Al alloy according to claim 1, wherein the pore diameter of the porous layer has a discontinuous change portion in an arbitrary section in the depth direction. 4. The A according to claim 2, wherein the pore diameter of the porous layer has a non-change portion in an arbitrary section in the depth direction.
1 or Al alloy vacuum chamber member. 5. The Al or Al alloy according to claim 1, wherein the anodic oxide coating contains two or more elements selected from the group consisting of C, S, N, P, F and B. Made vacuum chamber member. 6. The A according to claim 1, wherein an average particle diameter of crystallized substances and precipitates in the base material is 10 μm or less.
1 alloy vacuum chamber member. 7. The aluminum alloy vacuum according to claim 1, wherein the crystallized substances and precipitates in the base material are arranged in parallel with the surface of the member having the largest area on the surface of the member. Chamber member.