JP2001335989A - Anodic oxidized al material having excellent corrosion resistance, method for manufacturing the same and al parts for plasma atmosphere same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an anodic oxidized Al material which excellent corrosion resistance is be obtained even under a high-temperature corrosive atmosphere, a method for manufacturing the same and part for a plasma atmosphere using the same. SOLUTION: This anodically oxidized Al-base metallic material is formed with an anodically oxidized film on an Al-base metallic material and is formed by packing the fired bodies of an amorphous Si-containing materials, such as organic compounds containing >=10 at.% Si at >=50% of many cracks formed in the anodically oxidized film and has Si-O bonds. The Al-base metallic base material is manufactured by supplying an organic treating solution prepared by dissolving the organic compounds having the Si-O bonds by an organic solvent to the anodically oxidized film formed on the surface of the Al-base metallic material, then drying the organic treating solution supplied to the anodically oxidized film and firing the organic compounds after the drying at a firing temperature of >=100 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an anodized Al-based metal material having excellent corrosion resistance and a method for producing the same.
The l-base metal material is suitably used as a semiconductor microdevice manufacturing apparatus, or as a material for a reaction vessel or component exposed to a halogen-based gas such as chlorine, hydrogen chloride, or hydrogen bromide or its plasma.

[0002]

2. Description of the Related Art A vacuum chamber for a semiconductor manufacturing apparatus and various parts provided in the chamber are mainly formed of an Al-based metal material mainly composed of Al. These components (including the chamber) may be used in a chlorine-based or bromine-based corrosive gas environment, and the Al-based metal material forming the components is corroded by the corrosive gas and reacts with chlorides and the like. Product formation is a source of contamination in the manufacturing process. Further, at the time of cleaning a component, a gas component or a corrosion product adsorbed on the component may be dissolved in the cleaning water to generate a corrosive aqueous solution such as hydrochloric acid, which may corrode the Al-based metal. Therefore, in order to improve the corrosion resistance and plasma resistance of the Al-based metal material in a corrosive gas, as described in Japanese Patent Publication No. 53870/1993,
Anodizing treatment is performed on the base metal material.

[0003]

However, the anodic oxide film (Al-O, A
1-OH, Al-O-OH mixed layer) may have cracks.
Since the anodic oxide film is used in a high temperature atmosphere of about 00 ° C., cracks in the anodic oxide film may further increase or expand. For this reason, even though these parts are subjected to the anodic oxidation treatment, corrosion by corrosive gas invading from cracks becomes a problem. In particular, the anodic oxide film applied to various parts exposed to the plasma atmosphere of the semiconductor manufacturing equipment with an emphasis on plasma resistance is formed relatively thick in order to improve the plasma resistance. This tends to occur and it is difficult to obtain sufficient corrosion resistance.

Japanese Patent Application Laid-Open No. 6-316787 discloses a method for improving the corrosion resistance of an anodic oxide film, in which anodized aluminum is immersed in a solution containing alkoxysilane to fill the micropores of the anodic oxide film with SiO ₂ . Has been proposed, but the filling amount is small and SiO ₂
Is poor in flexibility and cracks occur in the anodic oxide film in a high-temperature atmosphere, and thus hardly contributes to the improvement of the corrosion resistance of the anodized Al-based metal material exposed to the high-temperature corrosive atmosphere.

An object of the present invention is to solve the above-mentioned problems, and to provide an anodized Al-based metal material having excellent corrosion resistance even in a high-temperature corrosive atmosphere, a method for producing the same, and an Al-based metal for a plasma atmosphere using the same. It is intended to provide parts.

[0006]

The anodized Al-based metal material of the present invention comprises an Al-based metal substrate having an anodized film formed thereon.
50% of many cracks formed in the anodized film
In the above, the Si— content having a Si content of 10 at% or more
A fired body of an amorphous Si-containing material having an O bond is filled with cracks at 1% or more of the crack volume.

Further, according to the method for producing an anodized Al-based metal material of the present invention, an organic compound having a Si—O bond dissolved in an anodized film formed on the surface of an Al-based metal substrate by an organic solvent is used. After supplying the processing solution, the organic processing solution supplied to the anodic oxide film is dried, and the dried organic compound is fired at a firing temperature of 100 ° C. or higher.

In carrying out this method, the Al-based metal substrate on which the anodic oxide film has been formed can be heated at a preheating temperature equal to or higher than the firing temperature, and then the organic processing solution can be supplied. Further, the Al-based metal substrate on which the anodized film is formed is held in boiling water or steam to seal pores formed on the anodized film, and then the organic solution can be supplied. Furthermore,
After sealing the pores formed in the anodized film, the Al-based metal substrate on which the anodized film is formed is heated at a preheating temperature equal to or higher than the firing temperature, and then the organic processing solution is supplied. can do. Further, in the case where the pore sealing treatment is not performed independently, an organic treatment solution containing 1% or more of water is supplied to the anodic oxide film, so that the crack is filled with the organic compound and the pores are filled. Sealing treatment can be performed.

The Al-based metal part for a plasma atmosphere of the present invention is a part including a plasma reaction vessel used in a plasma atmosphere, and the Al-based metal part for a plasma atmosphere is the anodized Al-based metal part of the present invention. It is formed of a base metal material.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Anodized aluminum-based metal
The anodized film formed on the surface of the material has cracks
Easy, immediately after the formation of the anodic oxide film without heating
Many cracks exist in the semiconductor manufacturing process
The heating further increases the number. Anodized film
Al oxides that make up
The anodic oxide film is not likely to corrode.
Corrosive gas or corrosive aqueous solution penetrates through the rack and the base material A
It is presumed that contact with l-base metal is one of the causes of corrosion resistance deterioration.
Is determined. Based on this estimation, the present inventor
Consider measures to effectively shut off cracks that become roads from outside air
did. In particular, corrosion from cracks at high temperatures becomes a problem
If the temperature changes, new cracks occur, existing
In order to prevent the crack from spreading, it is necessary to
Inorganic compound consisting of only Si—O (crystalline SiO 2) _Two)
Is inadequate due to the lack of flexibility and some flexibility
As a result of examining the fact that substances having properties are preferable,
Corrosive gas and corrosive aqueous solution to crack anodized film
Of non-crystalline Si-containing material containing Si-O showing corrosion resistance
The finding that filling with a fired body is effective,
It was completed.

That is, the anodized Al-based metal material of the present invention is an anodized Al-based metal material in which an anodized film is formed on an Al-based metal base material containing Al as a main component. In 50% or more of the formed cracks, a fired body of an amorphous Si-containing material having a Si-O bond having a Si content of 10 at% or more was filled in each crack by 1% or more of the crack volume. Things.

[0012] The Si content is at least 10 at%
A fired body of an amorphous Si-containing material having an -O bond is preferably obtained by supplying a solution of an organic compound (C-containing compound) having the same bond to an anodized film, drying, and firing as described later. The non-crystalline Si-containing material includes the organic compound and amorphous SiO ₂ . The organic compound may be in the form of any of a monomer, an oligomer and a polymer, and may be an organopolysiloxane or an organosilsesquioxane having a functional group such as a methyl group or a phenyl group in a side chain (for example, phenylsilsesquioxane). Oxane) and silanol. The Si content in the amorphous Si-containing material is 10
The reason why the content is set to at% or more is that if the Si content is less than 10 at%, Si—
This is because O-bonding is insufficient, and the filling property into cracks is insufficient. The organic compound is filled in a crack as a fired body. When the anodized Al-based metal material is washed with an organic solvent or water, the organic compound dissolves in the solvent when the material is not fired, which may reduce the outside air blocking effect and deteriorate the corrosion resistance. .

Further, in order to suppress intrusion of corrosive gas or aqueous solution from cracks, at least 50%
Preferably, 90% or more, more preferably all the cracks are filled with the sintered body of the amorphous Si-containing material. Further, the filling amount of the fired body in the crack is set to 1% or more of the volume of the crack. If the fired body is filled at the bottom of the crack where the Al-based metal substrate is exposed, an effect of blocking the outside air can be obtained. Therefore, a relatively small amount of 1% of the fired body is sufficient. The filling factor of the fired amorphous Si-containing material can be confirmed by observing an anodized cross section with a transmission electron microscope (TEM) provided with energy dispersive X-ray analysis (EDS). The Si content in the amorphous Si-containing material to be filled is not constant, and the actually measured value is affected by the surrounding Al oxide. However, the Si atomic fraction only needs to be 10% or more as an average value. Note that the amount of C in the amorphous Si-containing material in the crack may be extremely small, and it is difficult to specify the lower limit of C by an analytical electron microscope. When the filling amount is small, it is difficult to confirm the presence of a C—H bond or the like by other analysis methods such as infrared absorption.

Next, a method for producing the anodized Al-based metal material of the present invention will be described. Anodizing treatment is performed on the Al-based metal base material formed into a predetermined shape to prepare an Al-based metal base material having an anodic oxide film formed on the surface, and the Si content is 10 at. % Or more of Si-
An organic processing solution in which an organic compound having an O bond is dissolved in an organic solvent is supplied. The organic processing solution supplied to the anodic oxide film penetrates and fills many cracks formed in the anodic oxide film.

As the organic solvent, toluene, ethanol, isopropanol, butanol, methyl isobutyl ketone (MIBK), acetone, ethyl acetate, butyl acetate and the like can be used. The concentration of the organic compound in the organic treatment solution may be such that Si is usually about 0.1 to 6 mol / l, preferably about 0.5 to 3 mol / l.

As a method for supplying the organic solvent to the anodic oxide film, an organic treatment solution may be applied using a brush or cloth, or the Al-based metal substrate on which the anodic oxide film is formed may be applied to the organic treatment film. You may make it immerse in a solution. Also,
A coating technique using centrifugal force, which is called SOG (Spin on Glass) or coated glass in the field of electronic industry, can be used. Also, the number of times the organic processing solution is supplied is usually
It may be performed once, but may be repeatedly supplied plural times after the supply and drying.

After supplying the organic processing solution, the solvent in the solution is dried, and then the organic compound filled in the crack is fired. If the firing is insufficient, the organic compound dissolves in the organic solvent and is removed when the part formed of the anodized Al-based metal material is washed with the organic solvent, so that at least 100 ° C. or more, preferably Is 1
It is preferable to bake at 50 ° C. or higher. Further, it is desirable that the temperature be higher than the maximum temperature during use of the component. The upper limit of the firing temperature is not particularly limited as long as the mechanical properties of the Al-based metal substrate are not impaired. The firing time is 1
It may be about 0 to 120 minutes. By a suitable firing treatment, a fired body of the organic compound is obtained, and the fired body may contain amorphous SiO ₂ .

By the way, before the supply of the organic processing solution, a preheating treatment of heating at a preheating temperature higher than a baking temperature may be performed to introduce cracks in the anodic oxide film in advance or enlarge existing cracks. . As a result, the penetration of the organic treatment solution into the cracks is promoted, and the introduction of new cracks during baking and the expansion of the cracks can be suppressed. More preferably, it is desirable to heat at a preheating temperature equal to or higher than the maximum temperature during use. by this,
Generation of new cracks and expansion of cracks during use can be prevented, and more stable performance can be obtained.
The upper limit of the preheating temperature is not particularly limited as long as it is within a temperature range that does not impair the mechanical properties of the Al-based metal substrate. The heating holding time may be about 10 to 120 minutes.

For the purpose of improving the corrosion resistance and plasma resistance, the Al-based metal substrate on which the anodic oxide film is formed is immersed in boiling water or held in steam to seal the pores of the anodic oxide film. Hydration sealing can be performed. This sealing treatment is preferably performed before supplying the organic treatment solution. If the organic treatment solution is supplied first and the pores are filled with the organic compound as well as cracks, the intrusion of water into the pores is suppressed and the hydration reaction does not proceed.

When the preheating treatment is performed in advance, the hydration sealing treatment is first performed, then the preheating treatment is performed, and then the organic compound is filled into cracks and fired. Is preferably performed. If the preheating treatment is performed before the hydration sealing treatment, cracks newly introduced by the hydration sealing treatment may not exhibit the effect of the preheating treatment.

The hydration sealing treatment is carried out by using a water-containing organic treatment solution containing 1% or more, preferably 5% or more water in the organic treatment solution. The filling of the compound with cracks can be performed simultaneously. In this case, as the organic solvent used when preparing the organic treatment solution, a readily water-soluble solvent such as ethanol, isopropanol, butanol, or acetone is suitable. If the content of water is too large, it becomes difficult to dissolve the organic compound having the Si—O bond.
It is good to be less than about.

Depending on the supply amount of the organic treatment solution, the organic compound may form a coating film on the outermost surface of the anodic oxide film after filling cracks in the anodic oxide film. In this state, the effect of improving the corrosion resistance by the outermost coating film is added, and the corrosion resistance to a chlorine-based or bromine-based corrosive gas or aqueous solution is further improved particularly at a portion not exposed to plasma. However, the plasma resistance of the outermost coating film does not reach that of the anodic oxide film, and in an environment exposed directly to plasma, the coating film disappears in a short period of time, and the effect of improving the durability is small.

The anodized Al-based metal material of the present invention has excellent corrosion resistance in a high-temperature atmosphere, particularly in a plasma environment using a chlorine-based or bromine-based corrosive gas.
It is suitable as a vacuum chamber to be used by being exposed to these atmospheres and components such as electrodes used therein.

Hereinafter, the present invention will be described with reference to examples, but the present invention is not construed as being limited to the following examples. For example, as an Al-based metal substrate, A10
Pure Al-based alloys such as 50, Al-Mg-based alloys such as A5052, and Al-Mg-Si-based Al alloys such as A6061 and A6063 can be used. Further, the anodic oxide film can also be formed by performing anodic oxidation using an anodizing treatment solution such as a sulfuric acid type or an oxalic acid type as appropriate. The thickness of the anodic oxide film is not particularly limited. However, cracks easily occur in the anodic oxide film.
The improvement effect is remarkable in the case of a relatively thick film of about m or more.

[0025]

EXAMPLES As shown in Table 1 below, a commercially available Al alloy plate of A6061 or A5052 was prepared as an Al-based metal substrate, and anodized. The anodic oxidation is performed using a sulfuric acid-based or oxalic acid-based treatment solution. The electrolysis conditions of the sulfuric acid-based treatment solution are constant current electrolysis at a current of 2.5 A / dm ² , and the oxalic acid-based treatment solution is a constant potential electrolysis of 50 V at 20 μm Alternatively, an anodic oxide film having a thickness of 50 μm was formed.

Sample Nos. 1 to 6 were prepared using Si as an organic compound.
The Al alloy plate is immersed in an organic treatment solution obtained by dissolving a ladder type silicone oligomer having a —O bond and a CH ₃ group and a C ₆ H ₅ group in methyl isobutyl ketone in an amount of 20% by weight (2.2 mol / l of Si). Then pull it up and dry (about 140 ° C
-5 min), and then fired at the firing temperature shown in the same table for 30 minutes. On the other hand, Sample No. 7 had a silicone oligomer concentration of 2% by weight (Si was 0.22 mol / l),
No. 8 is the same as No. 1 to 6 after heating at 300 ° C. for 30 minutes. Sample No. 9 was the same as No. 8 after boiling water sealing. Sample No. 10 was obtained by immersing in an organic treatment solution in which 20% of the silicone oligomer and 10% of water were dissolved in ethanol, pulled up, dried, and baked at 300 ° C. for 30 minutes.

On the other hand, the sample No. 113 was anodized as it was, the sample No. 12 was anodized and sealed,
No. 13 contained 1% of ethyl silicate in terms of SiO _{2 and} 0.1% of hydrochloric acid. It was immersed in an ethyl alcohol solution containing 5% of O and 1% of water and dried at 130 ° C. for 1 hour (SiO ₂ filling treatment).

With respect to the sample prepared as described above, the cross section of the thin film of the anodic oxide film formed by the focused ion beam (FIB) method was observed by a transmission electron microscope (TEM) equipped with an energy dispersive X-ray detector. Then, when the Si concentration in the organic compound (fired body) filled in the crack was measured, the average Si concentration in the organic compound was 20 at.
%. For each sample, five visual fields including cracks were observed at a magnification of 15,000 (about 8 μm × 8 μm), and the percentage of cracks in which the organic compound (fired body) was filled by 1% or more by volume was determined.

The corrosion resistance of each sample was evaluated. Corrosion resistance was simulated at 300 ° C x 30 by simulating temperature changes in the actual use environment, plasma erosion and acid generation during cleaning.
After heating, buffing was performed and then immersed in a 7% HCl aqueous solution, the time until hydrogen generation was measured, and evaluated on a 4-point scale. The longer the measurement time, the more excellent the corrosion resistance. ◎ (excellent) when hydrogen is generated for more than 30 min, 15 min to 30 min
The following cases were evaluated as ○ (good), those between 5 min and less than 15 min as Δ (acceptable), and those less than 5 min as x (impossible). The results of these investigations are also shown in Table 1.

From Table 1, it can be seen that Sample Nos. 1 to 10 of the Examples
Good corrosion resistance even after buffing, which corresponds to plasma erosion, and especially 1% of organic compound (fired body)
In the case where the percentage of cracks filled as above was 100%, and in the case where the sealing treatment with boiling water and the preheating treatment were performed (No. 9), excellent corrosion resistance was exhibited.

[0031]

[Table 1]

[0032]

As described above, the anodized Al-based metal material of the present invention has an anodic oxide film and thus has excellent plasma resistance, and is resistant to corrosive gas or its corrosive aqueous solution in a high-temperature atmosphere. Has excellent corrosion resistance. Further, since the Al-based metal component for a plasma atmosphere according to the present invention is formed of the anodized Al-based metal material, it can be used as a component that is exposed to a plasma atmosphere caused by a high-temperature and corrosive gas such as a semiconductor manufacturing apparatus. Excellent in nature,
Its life can be improved.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Atsushi Hisamoto 1-5-5 Takatsukadai, Nishi-ku, Kobe City, Hyogo Prefecture Inside Kobe Research Institute, Kobe Steel Ltd. (72) Inventor Toshiyuki Tanaka Takatsuka, Nishi-ku, Kobe City, Hyogo Prefecture 1-5-5 Daiko Kobe Steel, Ltd. Kobe Research Institute

Claims (7)

[Claims] 1. An anodized Al-based metal material having an Al-based metal substrate having an anodized film formed thereon, wherein 50% of a large number of cracks formed in the anodized film are formed.
In the above, the Si— content having a Si content of 10 at% or more
An anodized Al-based metal material in which a fired body of an amorphous Si-containing material having an O bond is filled in a crack by 1% or more of the crack volume. 2. An organic processing solution in which an organic compound having a Si—O bond is dissolved by an organic solvent is supplied to the anodic oxide film formed on the surface of the Al-based metal base material, and then supplied to the anodic oxide film. A method for producing an anodized Al-based metal material, wherein the organic compound solution is dried and the dried organic compound is fired at a firing temperature of 100 ° C. or higher. 3. The manufacturing method according to claim 2, wherein the Al-based metal substrate on which the anodized film is formed is heated at a preheating temperature, and then the organic processing solution is supplied. Of producing an anodized Al-based metal material at a temperature not lower than the firing temperature. 4. An aluminum-based metal substrate having an anodized film formed thereon is held in boiling water or steam to seal pores formed in the anodized film, and then the organic solution is supplied. 2. The method for producing an anodized Al-based metal material according to item 2. 5. After sealing the pores formed on the anodized film, heating the Al-based metal substrate on which the anodized film is formed at a preheating temperature, and then supplying the organic processing solution. The method according to claim 4, wherein the preheating temperature is equal to or higher than the firing temperature. 6. The method for producing an anodized Al-based metal material according to claim 2, wherein the organic treatment solution contains 1% or more of water. 7. An Al-based metal part for a plasma atmosphere including a plasma reaction vessel used in a plasma atmosphere, wherein the Al-based metal part for a plasma atmosphere is the anodized Al-based metal material according to claim 1. Al-based metal parts for plasma atmosphere formed by the method described above.