JPH09176772A - Al alloy, and formation of fluorided passivating film excellent in corrosion resistance by using the al alloy - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an Al alloy for formation of a fluorided passivating film, used for the manufacture of various equipment for use in semiconductor manufacturing process and liquid crystal display manufacture and excellent in corrosion resistance, and a method for forming this fluorided passivating film excellent in corrosion resistance. SOLUTION: The fluorided passivating film is formed on the surface of a base material composed of Al alloy having a composition which consists of 2.0-4.5% Mg, 0.08-0.20% Zr, 0.003-0.015% Ti, and the balance Al with inevitable impurities and further contains, if necessary, 0.001-0.015% B and in which the contents of Si, Fe, Cu, Mn, Cr, and Zn as the inevitable impurities are controlled to <=0.03%, <=0.03%, <=0.02%, <=0.02%, <=0.02%, and <=0.02%, respectively.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an Al alloy for coating a fluorinated passivation film, and an Al alloy coated member obtained by coating the fluorinated passivation film on this Al alloy is used in a semiconductor manufacturing process or a liquid crystal display manufacturing process. The present invention relates to a method for forming a fluorinated passivation film, which is used as a member of various devices used in 1., and which has a characteristic of being more excellent in corrosion resistance than the conventional one on the surface of the Al alloy.

[0002]

2. Description of the Related Art Conventionally, various devices used in semiconductor manufacturing processes and liquid crystal display manufacturing have their surfaces exposed to highly corrosive chlorine gas, HF gas, etc.
Materials with excellent corrosion resistance, such as stainless steel, have been used. However, although stainless steel has excellent corrosion resistance, once corroded, it causes problems of heavy metal contamination, poor gas emission characteristics, and large specific gravity, which causes many problems in installation and handling in a clean room. It was desired to reduce the weight.

Therefore, as a member of various devices used in a semiconductor manufacturing process or a liquid crystal display manufacturing, an Al fluoride base film containing magnesium fluoride as a main component is formed on the surface of an Al alloy substrate containing magnesium.
An alloy coated member is provided (Japanese Patent Application Laid-Open No. 4-66657).
Reference).

Al on which this fluorinated passivation film is formed
As an alloy, JIS 5086 (wt%, Mg: 4.
0-5.0%, Si: 0.20% or less, Fe: 0.35
% Or less, Mn: 0.15% or less, Cu: 0.15% or less, Cr: 0.15% or less, Zn: 0.25% or less, T
i: 0.25% or less, the balance consisting of Al and unavoidable impurities) or JIS 5052 (% by weight)
Then, Mg: 2.2 to 2.8%, Si: 0.25% or less,
Fe: 0.40% or less, Mn: 0.10% or less, Cu:
0.10% or less, Cr: 0.15 to 0.35%, Zn:
Al alloys containing Mg such as 0.10% or less, and the balance consisting of Al and unavoidable impurities (hereinafter A).
1-Mg-based alloy) is used.
When the surface of the Al-based alloy is fluorinated, Mg of the Al-Mg-based alloy is more easily fluorinated than Al, so that a fluorinated passivation film containing magnesium fluoride as a main component is formed on the surface of the Al alloy. . It is considered that a Mg deficient layer can be formed at the boundary portion by forming the fluorinated passivation film, but the reason why the fluorinated passivation film is formed without forming the Mg deficient layer at the boundary portion is that the Al-Mg-based substrate is used. It is considered that this is due to the fact that Mg contained in the alloy is diffused and supplied from the inside and the reaction proceeds.

[0005]

[Problems to be solved by the invention]

(A) The conventional Al-Mg-based alloy is fluorinated to produce A
The formation of the fluorinated passivation film on the surface of the 1-Mg-based alloy substrate is usually performed by placing the Al-Mg-based alloy in a fluorine gas atmosphere heated to 350 ° C to 450 ° C. During the chemical treatment, the crystal grains of the conventional Al-Mg-based alloy grow and coarsen, making it difficult to form a sound fluorinated passivation film, and lowering the strength of the Al-Mg-based alloy. (B)
Since the members for semiconductor devices in recent years are exposed to an increasingly severe corrosive atmosphere, the conventional fluorinated passivation film does not have sufficient corrosion resistance, and further improvement in the corrosion resistance of the fluorinated passivation film is desired.

[0006]

Therefore, from this viewpoint, the present inventors have made Al-Mg, which becomes a base even when fluorinated.
As a result of conducting research to obtain a fluorinated passivation film with further excellent corrosion resistance, the strength of the alloys does not decrease,
If a predetermined amount of Ti is added to the Al-Mg-based alloy and B is added if necessary, the crystal grains are refined to prevent casting cracks, and if a predetermined amount of Zr is further added to this, fluorination treatment is performed. Even when exposed to the high temperature of 350 ° C to 450 ° C
The growth of the crystal grains of the 1-Mg-based alloy is not suppressed and the grains are not coarsened. Therefore, the strength of the Al-Mg-based alloy is prevented from lowering, and the fluorination-free oxide formed on the surface of the Al-Mg-based alloy is prevented. The research results were obtained such that the corrosion resistance of the active film is further improved.

The present invention was made on the basis of the results of such research, and (1)% by weight, Mg: 2.0-
4.5%, Zr: 0.08 to 0.20%, Ti: 0.0
And 0.01 to 15%, the balance consisting of Al and inevitable impurities, and Si as the inevitable impurities:
0.03% or less, Fe: 0.03% or less, Cu: 0.0
2% or less, Mn: 0.02% or less, Cr: 0.02% or less, Zn: Al: 0.02% or less, Zn: 0.02% or less. Mg:
2.0-4.5%, Zr: 0.08-0.20%, T
i: 0.003 to 0.015%, B: 0.001 to 0.
Containing 015%, the balance consisting of Al and unavoidable impurities, and Si: 0.03% or less, Fe: 0.03% or less, Cu: 0.02% or less, M as the unavoidable impurities.
n: 0.02% or less, Cr: 0.02% or less, Zn:
An Al alloy for coating a fluorinated passivation film having a composition regulated to 0.02% or less, (3) A base made of the Al alloy according to (1) or (2), and a magnesium fluoride-based passivation film on the surface thereof. It is characterized by the Al alloy coated member in which is formed.

The fluorinated passivation film which is more excellent in corrosion resistance than the conventional one is Mg: 2.0-4.5%, Zr: 0.08-
0.20%, Ti: 0.003 to 0.015%, the rest consisting of Al and unavoidable impurities, and Si: 0.03% or less as the unavoidable impurities, Fe: 0.
03% or less, Cu: 0.02% or less, Mn: 0.02%
Hereinafter, Cr: 0.02% or less, Zn: 0.02% or less of an Al alloy or B: 0.001 to 0.0
It can be formed by fluorinating an Al alloy containing 15%.

Therefore, the present invention provides (4) a method of forming a fluorinated passivation film having excellent corrosion resistance on the surface of an Al alloy substrate by fluorinating the surface of an Al alloy containing magnesium. A containing magnesium
1 alloy has Mg: 2.0 to 4.5%, Zr: 0.08 to
0.20%, Ti: 0.003 to 0.015%, the rest consisting of Al and unavoidable impurities, and Si: 0.03% or less as the unavoidable impurities, Fe: 0.0
3% or less, Cu: 0.02% or less, Mn: 0.02% or less, Cr: 0.02% or less, Zn: 0.02% or less. Or (5) a method of forming a fluorinated passivation film having excellent corrosion resistance on the surface of an Al alloy substrate by fluorinating the surface of an Al alloy containing magnesium. , Mg: 2.0 to 4.5%, Z
r: 0.08 to 0.20%, Ti: 0.003 to 0.0
15%, B: 0.001 to 0.015%, the rest consisting of Al and unavoidable impurities, and Si: 0.03% or less, Fe: 0.03% or less, Cu: 0. 02% or less, Mn: 0.02% or less, C
It is also characterized by a method of forming a fluorinated passivation film having excellent corrosion resistance, which comprises fluorinating the surface of an Al alloy regulated to r: 0.02% or less and Zn: 0.02% or less.

Mg: 2.0-4.5%, Zr: 0.
08 to 0.20%, Ti: 0.003 to 0.015%, the rest consisting of Al and unavoidable impurities, and Si: 0.03% or less as the unavoidable impurities, Fe:
0.03% or less, Cu: 0.02% or less, Mn: 0.0
2% or less, Cr: 0.02% or less, Zn: 0.02% or less Al alloy, or B: 0.001
The reason why a fluorinated passivation film that is more excellent in corrosion resistance than conventional ones can be obtained by fluorinating an Al alloy containing 0.015% to Si is as unavoidable impurities contained in the Al alloy.
0.03% or less, Fe: 0.03% or less, Cu: 0.0
By limiting the content to 2% or less, Mn: 0.02% or less, Cr: 0.02% or less, Zn: 0.02% or less, the amount of intermetallic compounds precipitated on the surface of the Al alloy is reduced, and further Z
The Al alloy containing 0.07 to 0.28% of r suppresses the growth of crystal grains of the Al alloy even if it is heated to 350 ° C. to 450 ° C. during the fluorination treatment. It is considered that this is due to the formation of a more stable fluorinated passive film with less friction at the boundary between the active film and the Al alloy, and thus with less internal strain.

The reason why the component composition of the Al alloy for coating the fluorinated passivation film of the present invention is limited as described above will be described. Mg: Mg is added to increase the strength of the aluminum material and to form a fluorinated passivation film, but if its content is less than 2.0%, the strength of the alloy containing Mg is reduced and the machinability is also improved. Is not preferable because it becomes defective, while
When the Mg content exceeds 4.5%, casting and rolling become difficult, and an intermetallic compound is formed to impair the integrity of the fluorinated passivation film. Therefore, the content of Mg is 1.5 to
It was set at 4.5%. The more preferable range of the Mg content is 2.5 to 3.5%.

Ti: Ti is a component that refines crystal grains, prevents casting cracks, and improves hot workability and machinability, but if the content is less than 0.003%, it is as described above. It is not preferable because the characteristics cannot be obtained,
On the other hand, if the Ti content exceeds 0.015%, a coarse intermetallic compound is formed and the soundness of the fluorinated passivation film is impaired, which is not preferable. Therefore, the content of Ti is set to 0.003 to 0.015%. A more preferable range of the Ti content is 0.004 to 0.010%.

B: B is a component that refines the crystal grains, prevents casting cracks, and improves hot workability and machinability, so it is added if necessary, but the content is 0.0.
If it is less than 01%, the above properties cannot be obtained, which is not preferable. On the other hand, if the content of B exceeds 0.005%, a coarse intermetallic compound is formed, and the fluorinated passivation film is sound. It is not preferable because it impairs sex. Therefore, the content of B is set to 0.001 to 0.005%.
A more preferable range of the content of B is 0.001 to 0.00
3%.

Zr: Zr is an Al--Mg based alloy 350
Prevents the crystal grains of the Al-Mg alloy from growing and coarsening and lowering the strength of the Al-Mg alloy when it is placed in a fluorine gas atmosphere heated to 50 ° C to 450 ° C for fluorination. Although it has an action, if its content is less than 0.08%, its effect is poor. On the other hand, if the Zr content exceeds 0.20%, a coarse intermetallic compound is formed, and fluorination is not achieved. It is not preferable because it impairs the health of the active membrane. Therefore, the Zr content is set to 0.08 to 0.20%.
A more preferable range of the Zr content is 0.09 to 0.15.

Inevitable impurities: Inevitable impurities are 0.04% or less (preferably 0.01%) for Si and Fe, respectively.
The following), Cu, Mn, Cr, and Zn must be individually limited to 0.02% or less (preferably 0.001% or less). If the permissible values are exceeded, coarse intermetallic compounds are formed and the integrity of the fluorinated passivation film is impaired, which is not preferable. In order to keep the allowable value of the unavoidable impurities within the above range, high-purity Al aluminum ingot is used as a raw material.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Purity: 99.992 as a raw material
% Al ingot, 99.95% Mg, 99.992% Al ingot with Al-5% Zr master alloy, 99.992%
Al-5% Ti master alloy using Al ingot, 99.992
% Al-5% Ti-1% B mother alloy using Al ingot is prepared, and these Al ingot and Mg, Al-5% Zr mother alloy, Al-5% Ti mother alloy and Al-5% are prepared. Ti-1
% B mother alloy is melted, and the obtained molten metal is filtered through a ceramic cartridge filter to prepare an ingot, and the obtained ingot is homogenized by holding at 540 ° C. for 6 hours, and then heated. 1 to 2 after cold rolling and then cold rolling
Al having the component composition shown in and having a thickness: 6 mm
Alloy plates A to T were produced. The Al alloy plates A to L are Al alloy plates within the composition range of the present invention, the Al alloy plates M to S are Al alloy plates outside the composition range of the present invention, and the Al alloy plate T is further included. Is A of JIS 5052
1 alloy plate.

[0017]

[Table 1]

[0018]

[Table 2]

The surfaces of the Al alloy plates A to T having the component compositions shown in Tables 1 and 2 were degreased and then cleaned, and the cleaned A
1 alloy plates A to T are charged into a chamber, the chamber is kept in a nitrogen atmosphere, baked at a temperature of 450 ° C. for 2 hours, and then the chamber is evacuated, and then high-purity fluorine gas is introduced. A fluorinated passivation film is formed on the surfaces of the baked Al alloy plates A to T by holding the fluorinated passivation film on the surfaces of the Al alloy plates A to T by holding at 5 ° C. for 5 hours. Invention Covering Member 1
.About.12, comparative coated members 1 to 7 and conventional coated members.

With respect to the coated members 1 to 12 of the present invention, the comparative coated members 1 to 7 and the conventional coated member, the length: 10 mm,
Width: A test piece was prepared by cutting it to a size of 20 mm, and the following corrosion resistance test was performed using this test piece.
~ Shown in Table 4.

(A) Corrosion resistance test by contact with hydrochloric acid vapor After contacting a test piece with 12N hydrochloric acid saturated vapor for 1 hour at room temperature, visual observation and microscopic observation of the appearance of the fluorinated passivation film on the surface of the test piece were performed. .

(B) Corrosion resistance test by immersion in hydrofluoric acid After a test piece was immersed in 0.1% hydrofluoric acid at room temperature for 1 hour,
The appearance of the fluorinated passivation film on the surface of the test piece was visually observed and microscopically observed.

(C) Plasma Corrosion Resistance Test 1 A test piece was irradiated with ₃₀ eV NF ₃ plasma for 1 hour, and then subjected to ES.
The residual rate of the fluorinated passivation film on the surface of the test piece was measured by CA depth analysis.

(D) Plasma corrosion resistance test 2 The test piece was irradiated with H ₂ plasma of 30 eV for 1 hour, and ESC was applied.
The residual rate of the fluorinated passivation film on the surface of the test piece was measured by A depth analysis.

[0025]

[Table 3]

[0026]

[Table 4]

From the results shown in Tables 1 to 4, the fluorinated passivation films of the coated members 1 to 12 of the present invention formed on the surfaces of the Zr-containing Al alloy plates A to L are Al alloys containing no Zr. It can be seen that the corrosion resistance is superior to the fluorinated passivation film of the conventional covering member formed on the surface of the plate T. But,
It can be seen that the fluorinated passivation films of the comparative coating members 1 to 7 formed on the surface of the Al—Mg based alloy having a composition deviating from the composition of the present invention do not show sufficient corrosion resistance.

[0028]

As described above, the present invention can provide members of various devices used in the semiconductor manufacturing process and the manufacturing of liquid crystal displays, which are more excellent in corrosion resistance than before, and greatly contribute to the development of various electronics industries. It can contribute.

Front Page Continuation (72) Inventor Yoshio Kume 4-3 Futaba-cho, Numazu City, Shizuoka Prefecture (72) Inventor Kazu Mikasa 1086-166 Oba, Mishima City, Shizuoka Prefecture (72) Inventor Magoro Maeno 2 Komeidai, Izumi City, Osaka Prefecture 2 -42-6 (72) Inventor Yoshinori Nakagawa 2-33-23 Hokucho, Izumi City, Osaka Prefecture

Claims (5)

[Claims] 1. By weight%, Mg: 2.0-4.5%, Zr: 0.08-0.20%, Ti: 0.003-0.015%, and the balance A
1 and unavoidable impurities, and the unavoidable impurities are Si: 0.03% or less, Fe: 0.03% or less, C
u: 0.02% or less, Mn: 0.02% or less, Cr:
Al for coating a fluorinated passivation film, which has a composition regulated to 0.02% or less and Zn: 0.02% or less
alloy. 2. By weight%, Mg: 2.0 to 4.5%, Zr: 0.08 to 0.20%, Ti: 0.003 to 0.015%, B: 0.001 to 0. 015%, the rest is Al
And inevitable impurities, and the inevitable impurities are Si: 0.03% or less, Fe: 0.03% or less, Cu:
0.02% or less, Mn: 0.02% or less, Cr: 0.0
An Al alloy for coating a fluorinated passivation film, which has a composition regulated to 2% or less and Zn: 0.02% or less. 3. An Al alloy coated member comprising the Al alloy according to claim 1 or 2 as a substrate, and a fluorinated passivation film formed on the surface thereof. 4. A method of forming a fluorinated passivation film having excellent corrosion resistance on the surface of an Al alloy substrate by fluorinating the surface of an Al alloy containing magnesium, wherein the Al alloy containing magnesium comprises: In wt%, Mg:
2.0-4.5%, Zr: 0.08-0.20%, T
i: 0.003 to 0.015%, the balance consisting of Al and inevitable impurities, and the inevitable impurities are S
i: 0.03% or less, Fe: 0.03% or less, Cu:
0.02% or less, Mn: 0.02% or less, Cr: 0.0
A method for forming a fluorinated passivation film having excellent corrosion resistance, which comprises using an Al alloy having a composition regulated to 2% or less and Zn: 0.02% or less. 5. A method of forming a fluorinated passivation film having excellent corrosion resistance on the surface of an Al alloy substrate by fluorinating the surface of an Al alloy containing magnesium, wherein the Al alloy containing magnesium comprises: In wt%, Mg:
2.0-4.5%, Zr: 0.08-0.20%, T
i: 0.003 to 0.015%, B: 0.001 to 0.
015% is contained, the balance is composed of Al and unavoidable impurities, and the unavoidable impurities are Si: 0.03% or less,
Fe: 0.03% or less, Cu: 0.02% or less, Mn:
0.02% or less, Cr: 0.02% or less, Zn: 0.0
A method for forming a fluorinated passivated film having excellent corrosion resistance, which comprises using an Al alloy having a composition regulated to 2% or less.