JPH1192912A - Metal material or metal film having fluorinated surface layer and fluorinating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a fluorinated surface layer excellent in corrosion resistance to halogen-based corrosive gas, excellent resistance to acid and alkali and excellent stability and durability by forcibly oxidizing the surface of a metal material or a metallic coating film and forming a fluorinated layer having specified film thickness on the surface. SOLUTION: The surface of a metal material such as aluminum, aluminum alloy, copper and copper alloy or a metallic coating such as nickel coating formed by electrolytic or electroless plating on a base body is forcibly oxidized. The forced oxidation is preferably carried out by using an oxidative material such as oxygen, especially oxygen produced on the anode by anodic oxidation method, or nitrogen suboxide, nitrogen peroxide, ozone, nitric acid, and hydrogen peroxide. Then the forcibly oxidized film is allowed to react with a fluorinating gas. As the fluorinating gas, fluorine, chlorine trifluoride, nitrogen fluorude or diluted gas of these compds. with inert gas are preferably used. Thereby, oxygen in the forcibly oxidized film is replaced by fluorine to form a fiuorlnated layer and a fluorine-diffused layer having >=1 μm film thickness.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal material or a metal film having a fluorinated surface and a method for fluorinating the same. More specifically, the present invention relates to a metal material or the like having a significantly improved corrosion resistance by forming a thick film made of a fluoride of the metal on the outermost layer of the metal material or the metal film, and using these in a semiconductor manufacturing apparatus or the like. This is a technique for realizing extremely effective corrosion resistance to halogen-based corrosive gases such as chlorine-based, fluorine-based, and bromine-based gases.

[0002]

2. Description of the Related Art Semiconductor manufacturing processes include hydrogen chloride (H).
Cl), boron trichloride (BCl ₃ ), fluorine (F ₂ ),
Nitrogen trifluoride (NF ₃ ), chlorine trifluoride (ClF ₃ ),
Halogen-based reactive and highly corrosive gases, such as hydrogen bromide (HBr), are used. When moisture is present in the atmosphere, it is easily hydrolyzed, producing hydrochloric acid, hydrofluoric acid, bromic acid, etc. The metal materials or metal films constituting valves, joints, pipes, reaction chambers, etc. that handle these gases easily corrode and cause problems.

[0003] These corrosive gases are decomposed into active atomic species and radical species by plasma, thermal decomposition, etc., and are used for etching an oxide film or a metal film on silicon or as a dry cleaning gas for a reaction chamber. Since it is also a gas, the amount of gas used has rapidly increased in recent VLSI manufacturing and liquid crystal manufacturing processes, and the highest degree of cleanliness and corrosion resistance in equipment materials such as the surface of a reactive chamber is required.

In the excimer laser field,
Since fluorine gas is mixed with a rare gas (krypton, neon argon) and oscillated, there is an extremely strong demand for corrosion resistance on the surface of the device material against generated fluorine radicals.

In order to solve such a problem, a commonly used material is stainless steel SUS316L which has been electropolished and baked at 250 ° C. before use. However, stainless steel does not satisfy the requirement of corrosion resistance, and various nickel-based alloys are used for high-temperature halogen gas such as hydrochloric acid.

However, these members still have many problems. First, the metal material itself is expensive, and its workability is poor as a device material member, and ultimately the device becomes considerably expensive. Further, its corrosion resistance is only for the limited components, for example, Hastelloy-C (N
i-Cr-Mo-W alloy) exhibits extremely excellent corrosion resistance to oxidizing acids, and exhibits excellent corrosion resistance even at room temperature, even with reducing hydrochloric acid, and also has pitting corrosion resistance. It shows remarkable corrosion resistance to corrosion. However, it has been pointed out that Hastelloy-C is inferior in corrosion resistance to the above-mentioned fluorine gas and fluorine radical and cannot be used.

A number of studies have been made on the passivation technology using fluorine gas. The use of fluorine gas on a nickel metal surface to form a passive film on the order of angstrom and exhibit a corrosion resistance function has been studied. Is known. Further, Japanese Patent Application Laid-Open No. Hei 2-263972 relates to an invention entitled "Metal material having a fluorinated passivation film formed thereon and an apparatus using the metal material". And
An apparatus using the metal material or metal film is disclosed. In the present invention, a fluorinated passivation film is formed by fluorine gas on at least one surface of nickel, nickel alloy, aluminum, aluminum alloy, copper, copper alloy, and chromium in a metal, and shows excellent corrosion resistance. . However, the thickness of the formed film is 1000 to 300
It is a very thin film of 0 Å. The surface state of the fluorinated aluminum, stainless steel, copper, and nickel plates in this publication is a polished surface.

[0008] Similarly, Japanese Patent Application Laid-Open No. 2-175855 discloses that
As a metal material or metal film on which a fluoridation passivation film is formed and a device using the metal material or metal film, a mixed fluoride layer of iron fluoride and chromium fluoride is fluorinated on a stainless steel surface with fluorine gas. It shows a method and a material for forming a passivation film into a submicron thin film, and shows excellent corrosion resistance. The thickness of the formed film is an extremely thin film of up to 4000 angstroms. In this publication, the SUS316L polishing plate is subjected to a fluorination treatment.

[0009]

The fluorinated passivation film formed in the above-mentioned publication has a film thickness of about 4000 angstroms or less, and is easily removed due to scratches or the like. It is hard to say that it is suitable as a material for semiconductor device manufacturing equipment in terms of life. The present invention
The purpose of the present invention is to solve the problems associated with the conventional technology as described above. The conventional passivation technology has a feature that the material surface is cleaned by polishing or the like and then passivated by fluorination treatment. However, surprisingly, if the surface before fluoridation is oxidized and passivated, and then fluoridation is performed, it is surprising that the passivated oxidized surface not only does not hinder fluoridation but rather forms a thick fluorinated layer. They discovered that they can be formed, and succeeded in providing a fluorinated layer that is thick, stable and excellent in durability, and a method for forming the same.

[0010]

According to the present invention, there is provided a metal material having a fluorinated surface layer, wherein a fluorinated layer having a thickness of 1 μm or more is formed after forcibly oxidizing the surface of a metal material or a metal film. Alternatively, there is provided a method for fluorinating a metal material or a metal film, which comprises forcibly oxidizing the metal film or the metal material or the metal film with an oxidizing substance, and then reacting the oxide film with a fluoride gas. Hereinafter, the present invention will be described in detail.

The metal to be fluorinated in the present invention is
Although any metal that is reactive with fluorine and forms a stable fluoride, nickel, copper, silver and aluminum are particularly preferred metals because fluorination significantly increases corrosion resistance. Iron, which is formed, is decomposed and dissociated by the moisture in the air, causing hydrofluoric acid on the metal surface, and in a usage environment containing moisture (open to the atmosphere), it also promotes corrosion. This is excluded in the present invention because there is a risk of causing a problem in practical use. The metal may be an alloy containing nickel or the like. Also,
In the present invention, the metal film to be fluorinated is a film formed by electrolytic plating, electroless plating, physical vapor deposition (PVD), or the like of nickel, copper, silver, aluminum, or an alloy containing one or more of these. Is mentioned.
As electrolytic plating, Ni plating, Ni-Cu plating,
Ni-W plating and the like can be mentioned. Examples of the electroless plating include Ni-P, Ni-B, Ni-P-W, and Ni-P-B. In addition, as the PVD, a sputtering method of Ni or an alloy thereof is used. Examples of the substrate on which the film is formed include various metal materials such as stainless steel, aluminum alloy, and steel, and various materials such as sintered metal, ceramics, and engineering plastic. Prior to forming a metal film, these materials are subjected to a known base treatment such as degreasing, pickling, polishing, or shot blasting.

In the description up to the following embodiments, a metal (alloy) material and a metal (alloy) film are abbreviated as “metal”.
In the present invention, the metal surface is once forcibly oxidized, and then the metal oxide film is reacted with fluorine. This is because in natural oxidation, the thickness of the oxide film is at most several tens to several hundreds angstroms, and the metal on which a strong oxide film is formed is limited to a specific metal such as aluminum. The forced oxidation method was adopted. When fluorination is performed after forced oxidation, a substitution reaction between oxygen and fluorine occurs to form a fluorinated layer. Therefore, the thickness of the fluoride layer increases in proportion to the thickness of the forced oxidation layer and reaches several tens of μm. However, if the thickness of the forced oxidation layer is too large, the adhesion to the base material is reduced. Conceivable. The thickness of the fluorinated film formed on the metal surface according to the present invention is controlled by controlling the thickness of the oxide film formed on the surface, so that the fluorinated film having a thickness larger than that obtained by so-called passivation is obtained. Can be provided. Aluminum alloys, copper, nickel, and alloys thereof readily have an affinity for oxygen and immediately form a natural oxide film on the surface in the air. Further, this natural oxide film keeps an extremely dense structure and is chemically stable. Therefore, at room temperature, the presence of this oxide film suppresses the diffusion of oxygen into the metal, and the natural oxide film is only tens to hundreds of angstroms, even if it has been exposed to the air for a long time. It is less than an ultra-thin film. Therefore, it is necessary to increase the thickness of the oxide film by so-called forced oxidation. The fluorinated layer formed in this manner has a level of practically sufficient durability in abrasion resistance, corrosion resistance and durability.

The fluorinated layer is a layer containing fluorine in a broad sense, but is preferably substantially composed of fluoride. Here, fluoridation has a substantial meaning, and it is not necessary to change the metal to 100% fluoride, but it is preferable that oxygen is replaced with fluorine to a level lower than the detection level. The metal does not necessarily need to be uniformly fluorinated, and the thickness of the fluorinated layer may be non-uniform, and the fluoride region and the fluorine diffusion region may be mixed. If the fluorination treatment is performed after the forced oxidation, the oxide layer is simply replaced with fluorine to generate a fluoride, and also the diffusion of the fluorine into the bulk metal occurs. As a result, a thick fluoride layer can be formed. In this case, the fluorinated layer is composed of a first layer substantially made of a metal fluoride and a second layer in which fluorine is diffused below this.

As the forced oxidizing means, so-called gas phase oxidation is also possible. In this case, oxygen or a mixed gas thereof with a neutral or inert gas is preferable. In addition, nitrous oxide, nitrous oxide, ozone, A mixed gas of hydrogen and a neutral or inert gas is also preferable. In this case, these gases are brought into contact with the metal at an elevated temperature. Another forced oxidation means includes liquid phase oxidation. This can be carried out by immersion in a solution of nitric acid, hydrogen peroxide solution or the like. Further, the metal material can be anodized using an electrolytic solution such as an alkali to form an oxide film on the surface. In this case, oxygen generated at the anode serves as forced oxidizing means. In the case of aluminum alloy, so-called alumite treatment (anodizing treatment)
It is widely known that an oxide film of several to several tens of microns can be formed on the surface of an aluminum alloy by using the method. As described above, the methods of the forced oxidation treatment can be combined in accordance with conditions such as an oxide film thickness to be formed and a metal type.

Similarly, the fluorination treatment is performed by using a 100% gas such as fluorine, chlorine trifluoride, or nitrogen trifluoride, or a gas obtained by diluting these gases with an inert gas such as nitrogen, helium, or argon; This is a manufacturing method in which an oxide film formed on the outermost layer on a metal surface is reacted with a plasma gas such as the above to obtain a fluorine diffusion layer or a fluoride film. Specifically, it may be performed as follows. That is, the metal as described above is installed in a normal-pressure gas-phase flow type reaction furnace, and the reaction furnace is heated to a predetermined temperature under a flow of an oxidizing gas, maintained for a predetermined time, and then fluorinated at a predetermined temperature. The surface may be fluorinated by filling with a gas and reacting for a predetermined time. In this case, the metal is degreased and dehydrated in a usual manner before being charged into the reaction furnace to increase the purity of the forced oxide film formed thereafter and have no defects. However, since the thin native oxide film of several tens angstroms or less remaining on the metal surface is forcibly oxidized together with the bulk, it is not necessary to remove it before the forced oxidation.

Further, the temperature of the reaction furnace is preferably from 200 ° C. to 600 ° C., particularly preferably from 300 ° C. to 500 ° C. in the forced oxidation of nickel and copper. The reaction time is generally preferably 1 hour to 48 hours, particularly preferably 3 hours to 24 hours.
Aluminum is preferably formed by anodic oxidation. Similarly, the fluorination temperature is usually 100 ° C to 700 ° C under normal pressure.
Particularly, the temperature is preferably from 150 ° C to 500 ° C. The reaction time is generally preferably 1 hour to 48 hours, particularly preferably 3 hours to 24 hours. Below these preferred lower limit temperatures and times, the oxygen in the forced oxidation layer is not sufficiently replaced by fluorine, and the diffusion of fluorine from the outermost surface is not sufficient. And cracks occur in the formed film.

[0017]

Next, the present invention will be described with reference to an electrolytic nickel plating film,
An example in which the electroless nickel alloy plating film is fluorinated will be described in detail. However, the present invention is not limited by the following examples.

Base treatment example Production example 1 (electrolytic nickel plating film) NiSO ₄ (nickel sulfate), N
Plating was performed using a plating agent composed of iCl ₂ (nickel chloride), H ₃ BO ₃ (boric acid), and a brightener. After a stainless steel (SUS316L) was preliminarily subjected to a base pretreatment by pickling, a film was formed at a current of 1 A / dm ^{2 for} a predetermined time.

Production Example 2 (Electroless Nickel Plating Film) A so-called chemical nickel plating, a commercial chemical for acidic chemical nickel plating by reduction of hypophosphite has been put to practical use. In this production example, a commercially available chemical nickel plating chemical using dimethylamine borane as a reducing agent and a commercially available chemical chemical nickel plating, that is, nickel-phosphorous plating (Ni-P alloy plating), which emphasizes corrosion resistance, were used.
These agents are mainly composed of NiSO ₄ which is a metal component.
(Nickel sulfate) 25g / L, NaHP as reducing agent
It is composed of 20 g / L of O ₂ (hypophosphorous acid), a complexing agent, a stabilizer, and a brightener. In the same manner as in Production Example 1, after a base plate pretreatment was applied to a stainless steel plate, it was immersed in a plating solution tank heated to 90 ° C. and reacted for a predetermined time to form a film.

Production Example 3 (Electroless nickel alloy plating skin
Film) A commercially available chemical for alkaline chemical plating using a nickel-phosphorous-tungsten (Ni-PW) bath, which emphasized abrasion resistance and corrosion resistance after heat treatment, was used. This chemical has a metal component of NiSO ₄ (nickel sulfate) 15 g /
L, Na ₂ WO ₃ (sodium tungstate), 20 g / L of NaHPO ₂ (hypophosphorous acid) as a reducing agent, a complexing agent,
Consists of stabilizers and brighteners. After applying a predetermined pre-treatment to the stainless steel plate as in the above examples, it was immersed in a plating solution tank heated to 85 ° C. and reacted for a predetermined time to form a film.

Production Example 4 As an example of a so-called aluminum alloy material, A5083 was subjected to surface mirror polishing, and then left in the air for 30 days.
A natural oxide film was sufficiently formed on the surface to obtain a test piece.

Production Example 5 As an example of a copper alloy material, a so-called C1100P copper material was subjected to surface mirror polishing, and then left in the air for 30 days to sufficiently form a natural oxide film on the surface to obtain a test piece. .

Example 1 A test piece prepared by the method described in Production Agent 1 was mounted in a normal-pressure gas-phase flow reactor, and subjected to pre-baking at 200 ° C. for 1 hour under reduced pressure to obtain a surface. After releasing the adsorbed moisture, etc., 50% while introducing oxygen gas (99.999%).
Heat to 0 ° C. The temperature was maintained for 12 hours to forcibly oxidize the metal surface. Thereafter, the temperature is lowered while replacing the oxygen gas with a nitrogen gas. When the temperature reaches 400 ° C, 20
% F ₂ gas (diluted with nitrogen) is introduced and replaced. After the complete substitution, the surface was kept for 24 hours, and the surface was fluorinated. After a predetermined time, the fluorine gas is replaced with nitrogen gas.
After holding for a time, the temperature was lowered.

Example 2 A test piece prepared by the method described in Production Example 1 was mounted in a normal-pressure gas-phase flow reactor, and subjected to a pretreatment for firing at 200 ° C. for 1 hour under reduced pressure. Oxygen gas (99.999%)
And the temperature is raised to 500 ° C. At that temperature 1
Holding for 2 hours, the metal surface was forcibly oxidized. Thereafter, the gas is replaced with nitrogen, and at that temperature, 20% F ₂ gas (diluted with nitrogen) is introduced and replaced. After the complete replacement, the surface was kept for 12 hours, and the surface was fluorinated. After a predetermined time, nitrogen gas was introduced and replaced, the temperature was maintained for 1 hour, and the temperature was lowered.

Example 3 A test piece prepared by the method described in Production Example 2 was mounted in a normal-pressure gas-phase flow reactor, and subjected to a pretreatment for firing at 200 ° C. under reduced pressure for 1 hour. Oxygen gas (99.999%)
, And the temperature is raised to 500 ° C. The temperature was maintained for 12 hours to forcibly oxidize the metal surface. Thereafter, the temperature is lowered while replacing the oxygen gas with a nitrogen gas. When the temperature reached 300 ° C., 20% F ₂ gas (diluted with nitrogen) was introduced.
Replace. After the complete replacement, the surface was kept for 12 hours, and the surface was fluorinated. After a predetermined time, the fluorine gas was replaced with nitrogen gas.

Example 4 A test piece prepared by the method described in Production Example 2 was mounted in a normal-pressure gas-phase flow reactor, and subjected to a pretreatment for firing at 200 ° C. under reduced pressure for 1 hour. Oxygen gas (99.999%)
And the temperature is raised to 500 ° C. At that temperature 1
Holding for 2 hours, the metal surface was forcibly oxidized. Thereafter, the gas is replaced with nitrogen, and at that temperature, 20% F ₂ gas (diluted with nitrogen) is introduced and replaced. After the complete replacement, the surface was kept for 12 hours, and the surface was fluorinated. After a predetermined time, nitrogen gas was introduced and replaced, the temperature was maintained for 1 hour, and the temperature was lowered.

Example 5 A test piece prepared by the method described in Production Example 3 was mounted in a normal-pressure gas-phase flow reactor, and subjected to pre-baking at 200 ° C. for 1 hour under reduced pressure. Oxygen gas (99.999%)
, And the temperature is raised to 500 ° C. The temperature was maintained for 12 hours to forcibly oxidize the metal surface. Thereafter, the temperature is lowered while replacing the oxygen gas with a nitrogen gas. 300 ℃
, 20% F ₂ gas (diluted with nitrogen) is introduced and replaced. After the complete replacement, the surface was kept for 12 hours, and the surface was fluorinated. After a predetermined time, the fluorine gas was replaced with nitrogen gas.

Example 6 A test piece prepared by the method described in Production Example 3 was mounted in a normal-pressure gas-phase flow reactor, and subjected to a pretreatment for firing at 200 ° C. for 1 hour under reduced pressure. Oxygen gas (99.999%)
, And the temperature is raised to 500 ° C. The temperature was maintained for 12 hours to forcibly oxidize the metal surface. Thereafter, the gas is replaced with nitrogen, and at that temperature, 20% F ₂ gas (diluted with nitrogen) is introduced and replaced. After the complete replacement, the surface was kept for 12 hours, and the surface was fluorinated. After a predetermined time, nitrogen gas was introduced and replaced, the temperature was maintained for 1 hour, and the temperature was lowered.

Example 7 As an example of a so-called aluminum alloy material, A5083 was subjected to surface mirror polishing, and the test piece was mounted in a normal-pressure gas-phase flow type reaction furnace and fired at 200 ° C. under reduced pressure for 1 hour. After the treatment, the temperature is raised to 500 ° C. while introducing oxygen gas (99.999%). Hold at that temperature for 8 hours,
The metal surface was forcibly oxidized. Thereafter, the gas was replaced with nitrogen, and the temperature was lowered to obtain a test piece.

Example 8 As an example of gas phase oxidation of a copper alloy material, a so-called C1100P copper material was subjected to surface mirror polishing, and a test piece was mounted inside a normal-pressure gas-phase flow type reaction furnace. After the pre-firing treatment for one hour, the temperature is raised to 500 ° C. while introducing oxygen gas (99.999%). The temperature was maintained for 8 hours to forcibly oxidize the metal surface. Thereafter, the gas was replaced with nitrogen, and the temperature was lowered to obtain a test piece.

Example 9 A test piece prepared by the method described in Production Example 2 was heated at 50 ° C.
Immersed in a 5% aqueous solution of nitric acid for 10 minutes and further washed thoroughly with pure water.
The surface was left to oxidize over time. The test piece was mounted in a normal-pressure gas-phase flow reactor, introduced with nitrogen gas, replaced with a gas, pre-baked at 200 ° C. for 1 hour under reduced pressure, and then cooled.

COMPARATIVE EXAMPLE 1 A test piece prepared by the method described in Production Example 3 was mounted in a normal-pressure gas-phase flow reactor, and subjected to a pretreatment for firing at 200 ° C. under reduced pressure for 1 hour. Raise the temperature and raise the furnace temperature to 40
When the temperature reaches 0 ° C., 20% F ₂ gas (nitrogen dilution) is introduced. The metal material was kept as it was for 6 hours to perform fluorination. This is a so-called widely known passivation treatment method for nickel materials. Thereafter, nitrogen gas was introduced and replaced at a predetermined temperature, and the temperature was maintained for 1 hour and then the temperature was lowered.

Measurement Results of Film Thickness FIG. 1 shows that the test piece of Example 4 was subjected to XPS (X-ray Pho).
5 shows the results of analysis by T.Electron spectroscopy. The elements detected on the surface are Ni,
There were four elements of F, O and C. The peak of Ni is greatly shifted to a higher energy side than that of the oxide, which indicates the bond with F which is an electron donor. In addition, C and O were removed by argon ion sputtering for several minutes, and were not detected. From this, it is considered that both C and O are caused by moisture and dirt adsorbed on the surface. Further, even when etching was performed by argon ion sputtering for as long as 100 minutes, there was no change in the detection pattern. The thickness of the fluorinated layer was determined based on the depth at which fluorine atoms were detected by argon sputtering. However, SiO ₂ on Si whose film thickness is known in advance
The same measurement was performed for the oxygen detection depth of the thin film, and the sputter rate was measured. The sputter rate was 115 Å / min (hereinafter referred to as “SiO ₂ correction”). As a result, it was found that the thickness of the fluorinated layer reached 1.2 μm or more.

Production Examples 1, 2, 3, and Examples 2, 4,
2, 3, 4, 5, 6, and 7 show the results of X-ray diffraction analysis of the test piece prepared in 6 by the thin film method. In FIG. 2, only the peak of metal Ni is detected, and FIG.
4, a broad peak of Ni—P or Ni—P—W was obtained, and it was confirmed that the sample was in an amorphous state. In addition, X obtained when heat treatment was performed at 400 ° C. for 3 hours in a nitrogen gas atmosphere.
From the line diffraction, it is confirmed that Ni and Ni ₃ P are crystallized and formed. FIGS. 5, 6, and 7 show the results of X-ray diffraction for Examples 2, 4, and 6 in which each of them was fluorinated. From FIG. 5, the formation of nickel fluoride (NiF ₂ ) on the nickel metal surface was confirmed.

FIG. 6 shows that the diffraction peak of Ni or Ni ₃ P is very slight, and NiF is almost the main peak.
_Two peaks were detected in large intensity. The measurement by the thin film method is performed at an incident angle θ of X-ray = 1 °, and the analysis depth at this time is theoretically 2.1 μm from the surface.
Fluoride on the order of μm is thickened on the surface of electroless nickel.

Similarly, FIG. 7 also shows that the diffraction peak of Ni or Ni ₃ P was very slightly recognized, and the NiF ₂ peak was detected as a major peak almost in terms of intensity. The result was almost the same as that of Example 6, and there was no significant difference in the surface state formed.

FIG. 8 shows the test piece of Example 3 as AES (Aug).
er Electron Spectroscopy)
Shows the results of the analysis. The element detected on the surface is N
There were four elements of i, F, O and C. Table 1 shows an element composition table in the outermost layer. C and O attributed to moisture and dirt adsorbed on the surface were removed by argon ion sputtering for several minutes, and were not detected. Ni
The atomic ratio of F and F is about 1: 2. In addition to the analysis result of the X-ray diffraction analysis described above, nickel fluoride (NiF
₂ ) was observed. When argon ion sputtering was further performed until no fluorine was detected, the detection intensity of fluorine began to decrease after about 90 minutes,
Since almost no detection was made after about 150 minutes, the etching rate of argon ion sputtering was 115 Å / min (SiO ₂ correction), and the thickness of the fluoride layer including the fluorine diffusion layer was 1.7 μm. It was confirmed that the film was thickened on the order of μm.

[0038]

[Table 1]

FIG. 9 shows the result of analyzing the test piece of Example 4 by AES. The elements detected on the surface were as described in Example 3 above.
Similarly to the above, there were four elements of Ni, F, O and C. Table 2 shows the element composition in the outermost layer. Moisture adsorbed on the surface and C and O, which are considered to be caused by contamination, were removed by argon ion sputtering for several minutes, and were not detected. The atomic ratio of Ni to F was about 1: 2, and the formation of nickel fluoride (NiF ₂ ) on the outermost layer was recognized in combination with the analysis result of the X-ray diffraction analysis described above. Argon ion sputtering was further performed, and there was no significant change in the surface condition even after 280 minutes, and it was confirmed from the etching rate of argon ion sputtering that the film thickness (in terms of SiO ₂ ) was 3.2 μm or more and the film was thickened. Was.

[0040]

[Table 2]

FIG. 10 shows the result of analyzing the test piece of Comparative Example 1 by AES. The elements detected on the surface are Ni, F,
There were four elements, O and C. Table 3 shows an element composition table of the outermost layer. Moisture adsorbed on the surface and C and O, which are considered to be caused by contamination, were removed by argon ion sputtering for about 1 minute, and were not detected. Although the atomic ratio of Ni to F was about 1: 2, the detection intensity of fluorine began to decrease in a few minutes from the start of sputtering, and was stopped in about 20 minutes. The etching rate of argon ion sputtering is 115 angstroms /
(Correction of SiO ₂ ), the film thickness including the fluorine diffusion layer was 2300 angstroms, and it was confirmed that the formed film was a sub-μm-order fluoride film.

[0042]

[Table 3]

Effect Example 1 Table 4 shows the results of conducting corrosion resistance tests on various materials. The corrosion resistance evaluation test was carried out at room temperature (25%
° C) It was represented by the weight loss of various materials when immersed for 24 hours. The surface-treated test pieces formed in Production Examples 2 and 3 and the test pieces of Examples 3, 4, 5, and 6 were used as comparative materials. As a result of measuring and comparing the amount of weight loss when taken out after 24 hours, Example 5 had the least amount of reduction in test. Example 3 shows the change in appearance.
In No. 5, pitting occurred on the edge of the test piece and the like. Except for this point, the amount of reduction in the test was smaller in each of the examples than in the electroless nickel plated test pieces of Production Examples 2 and 3. . This indicated that the test piece having a fluoride formed on the surface was extremely excellent in corrosion resistance.

[0044]

[Table 4] Test conditions-35% hydrochloric acid, 25 ° C, soak for 12 hours

Effect Example 2 FIG. 11 (Table 5) shows the results of performing a corrosion resistance test on the test piece of Example 3. As the corrosion resistance evaluation test, 20% nitric acid, 50% hydrofluoric acid, 20% sulfuric acid, 20% phosphoric acid,
28% ammonia water, 28% caustic soda, 50% formic acid,
A solution or drug such as 20% acetic acid, oxalic acid, organic solvent (acetone), ethanol, EDTA, tetramine, hydroxylamine hydrochloride is prepared, and each solution is added at room temperature (30%).
° C) The weight loss of various materials when immersed for 24 hours was shown. In any of the test solutions, the test piece of Example 3
Compared with the electroless nickel-plated test piece of Production Example 2 which was not fluorinated, it exhibited excellent corrosion resistance in terms of corrosion weight loss and appearance observation.

Effect Example 3 Table 6 shows the results of the wear resistance test performed on the test pieces of Production Example 2 and Examples 3 and 4 using a scratch tester.
The coefficient of static friction was not significantly different between Production Example 2 and Examples 3 and 4, but the coefficient of dynamic friction was
Examples 3 and 4, which were subjected to the fluoridation treatment, showed about half the value of Production Example 2, indicating excellent sliding properties.

[0047]

[Table 6] (Note) Abrasion resistance-Using a scratch tester, the pin was continuously slid on a test piece under a constant load (300 g), and the number of times until the film was broken was indicated.

Also, as a result of a wear resistance test under a constant load,
The number of times of sliding until the film was damaged was only one in Production Example 2, whereas 30 in Example 3 and 20 in Example 4.
It showed sliding friction characteristics and film durability as many as eight times. In particular, in Example 4 in which a thickened μm-order fluorinated compound film was formed, the abrasion resistance and durability exhibited values higher than those of electroless nickel plating, so that the performance was at a level that could withstand practically enough. Turned out to have.

REFERENCE EXAMPLE 1 FIG. 12 shows the result of analyzing by AES the difference between a natural oxide film formed on an aluminum alloy material and a vapor-phase oxide film formed by forced oxidation. Since the natural oxide film formed on the surface of the test piece of Production Example 4 takes about 5 minutes or more until the detection intensity of O is halved, the etching rate is 115 Å / min (in terms of SiO ₂ ). About 550
Angstrom. On the other hand, the oxide film of the test piece forcibly oxidized in the gas phase of Example 7 was about 250
It can be seen that it reaches 0 angstroms.

Reference Example 2 FIG. 13 shows the results of analysis by AES of the difference between a natural oxide film formed on a copper material and a vapor-phase oxide film formed by forced oxidation. Since the natural oxide film formed on the surface of the test piece of Production Example 5 takes about 20 seconds until the O detection intensity is reduced by half, the etching rate is also 115 Å / min (in terms of SiO ₂ ). Was about 40 angstroms. On the other hand, the oxide film of the test piece which was forcibly oxidized in the gas phase in Example 8 was not removed by argon ion sputtering for 80 minutes, and it can be seen that the film thickness reached about 1 μm or more. .

Reference Example 3 FIG. 14 shows the result of analyzing the difference between the liquid phase oxide film and the gas phase oxide film formed on the test piece of Production Example 2 by AES. The oxide film formed on the surface of the test piece of Example 9 by liquid phase oxidation had a time required for the detection intensity of O to be reduced by half to about 100 seconds. Similarly, the etching rate was set to 115 Å / min (SiO 2). ₍₂ conversions), it was about 200 angstroms. On the other hand, the thickness of the oxide film of the test piece taken out of the reactor at the stage of forcibly oxidizing with oxygen gas in Example 3 is such that O is removed from the surface by argon ion sputtering for about 55 minutes. It can be seen that the thickness of the oxide film has reached about 0.6 microns.

[0052]

The thick fluorinated layer achieved by the present invention is excellent in acid resistance and alkali resistance, and is extremely effective as a device member mainly for semiconductor-related equipment. Therefore, the metal material or metal film on which the surface fluorine layer is formed according to the present invention is extremely effective as a device for manufacturing a semiconductor device and a device member for vacuum-related equipment.

[Brief description of the drawings]

FIG. 1 is a chart showing XPS spectrum measurement results of Example 4.

FIG. 2 is a chart showing an analysis result by the XDF thin film method of Production Example 1.

FIG. 3 is a chart showing an analysis result by an XDF thin film method of Production Example 2.

FIG. 4 is a chart showing an analysis result by the XDF thin film method of Production Example 3.

FIG. 5 is a chart showing an analysis result by the XDF thin film method of Example 2.

FIG. 6 is a chart showing an analysis result by the XDF thin film method of Example 4.

FIG. 7 is a chart showing an analysis result by the XDF thin film method of Example 6.

FIG. 8 is a chart showing a measurement result of a surface composition by AES in Example 3.

FIG. 9 is a chart showing a result of measurement of a fluoride film by AES in Example 4.

FIG. 10 is a chart obtained by analyzing a test piece of Comparative Example 1 by AES.

FIG. 11 is a table (Table 5) showing the results of performing a corrosion resistance test on the test pieces of Production Examples 2 and 3.

FIG. 12 is a graph showing measurement results of a natural oxide film of an Al alloy material and an oxide film AES formed by vapor phase oxidation.

FIG. 13 is a graph showing measurement results of a native oxide film of Cu metal and an oxide film AES formed by vapor phase oxidation.

FIG. 14 is a graph showing measurement results by an oxide film AES by vapor phase oxidation and liquid phase oxidation of an NIP film.

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] September 2, 1998

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0004

[Correction method] Change

[Correction contents]

In the excimer laser field,
Fluorine gas a noble gas (krypton, neon, an argon)
Therefore, there is an extremely strong demand for the corrosion resistance of the surface of the device material against the generated fluorine radicals.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0007

[Correction method] Change

[Correction contents]

A number of studies have been made on the passivation technology using fluorine gas. The use of fluorine gas on a nickel metal surface to form a passive film on the order of angstrom and exhibit a corrosion resistance function has been studied. Is known. Further, Japanese Patent Application Laid-Open No. Hei 2-263972 relates to an invention entitled "Metal material having a fluorinated passivation film formed thereon and an apparatus using the metal material". And
An apparatus using the metal material or metal film is disclosed. In this publication , a fluorinated passivation film is formed by fluorine gas on at least one surface of nickel, nickel alloy, aluminum, aluminum alloy, copper, copper alloy, and chromium in a metal, and shows excellent corrosion resistance. . However, the thickness of the formed film is 1000 to 300
It is a very thin film of 0 Å. The surface state of the fluorinated aluminum, stainless steel , copper, and nickel plates in this publication is a polished surface.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction contents]

[0008] Similarly, Japanese Patent Application Laid-Open No. 2-175855 discloses that
As a metal material or metal film on which a fluoridation passivation film is formed and a device using the metal material or metal film, a mixed fluoride layer of iron fluoride and chromium fluoride is fluorinated on a stainless steel surface with fluorine gas. It shows a method and a material for forming the passivation film as a submicron thin film , and shows excellent corrosion resistance. The thickness of the formed film is an extremely thin film of up to 4000 angstroms.
In this publication, the SUS316L polishing plate is subjected to a fluorination treatment.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0012

[Correction method] Change

[Correction contents]

In the description up to the following embodiments, a metal (alloy) material and a metal (alloy) film are abbreviated as “metal”.
In the present invention, the metal surface is once forcibly oxidized, and then the metal oxide film is reacted with fluorine. This is a natural oxidation
Since the thickness of the oxide film is at most several tens to several hundreds of angstroms and the metal on which a strong oxide film is formed is limited to a specific metal such as aluminum, the present invention employs a forced oxidation method. I decided that. When fluorination is performed after forced oxidation, a substitution reaction between oxygen and fluorine occurs to form a fluorinated layer. Therefore, the thickness of the fluoride layer increases in proportion to the thickness of the forced oxide layer and reaches several tens of μm. However, if the thickness of the forced oxide layer is too large, the adhesion to the base material is reduced. Conceivable. The thickness of the fluoride film formed on the metal surface according to the present invention is controlled by controlling the thickness of the oxide film formed on the surface, so that the fluoride film having a greater thickness than that obtained by so-called passivation is obtained. Can be provided. Aluminum alloys, copper, nickel, and alloys thereof readily have an affinity for oxygen and immediately form a natural oxide film on the surface in the air. Also,
This natural oxide film keeps an extremely dense structure and is chemically stable. Therefore, at room temperature, the diffusion of oxygen into the metal is suppressed by the presence of this oxide film, and even if it has been exposed to the air for a long time, the natural oxide film has a thickness of only tens to hundreds of angstroms. It is less than an ultra-thin film. Therefore, it is necessary to increase the thickness of the oxide film by so-called forced oxidation. The fluorinated layer formed in this manner has a level of practically sufficient durability in abrasion resistance, corrosion resistance and durability.

[Procedure amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0018

[Correction method] Change

[Correction contents]

Base treatment example Production example 1 (electrolytic nickel plating film) NiSO ₄ (nickel sulfate), N
Plating was performed using a plating agent composed of iCl ₂ (nickel chloride), H ₃ BO ₃ (boric acid), and a brightener. After a stainless steel (SUS316L) was preliminarily subjected to a pre-treatment by pickling, a current was applied at a current density of 1 A / dm ^{2 for} a predetermined time to form a film.

[Procedure amendment 6]

[Document name to be amended] Statement

[Correction target item name] 0021

[Correction method] Change

[Correction contents]

Production Example 4 As an example of an aluminum alloy material, so-called A5083 was subjected to surface mirror polishing, and then left in the air for 30 days.
A natural oxide film was sufficiently formed on the surface to obtain a test piece.

[Procedure amendment 7]

[Document name to be amended] Statement

[Correction target item name] 0023

[Correction method] Change

[Correction contents]

Example 1 A test piece prepared by the method shown in Production Example 1 was mounted in a normal-pressure gas-phase flow reactor, and subjected to a pre-baking process at 200 ° C. for 1 hour under reduced pressure to obtain a surface. After releasing the adsorbed moisture, etc., 50% while introducing oxygen gas (99.999%).
Heat to 0 ° C. The temperature was maintained for 12 hours to forcibly oxidize the metal surface. Thereafter, the temperature is lowered while replacing the oxygen gas with a nitrogen gas. When the temperature reaches 400 ° C, 20
% F ₂ gas (diluted with nitrogen) is introduced and replaced. After the complete substitution, the surface was kept for 24 hours, and the surface was fluorinated. After a predetermined time, the fluorine gas is replaced with nitrogen gas.
After holding for a time, the temperature was lowered.

[Procedure amendment 8]

[Document name to be amended] Statement

[Correction target item name] 0035

[Correction method] Change

[Correction contents]

FIG. 6 shows that the diffraction peak of Ni or Ni ₃ P is very slight, and NiF is almost the main peak.
_Two peaks were detected in large intensity. The measurement by the thin film method is performed at an incident angle θ of X-ray = 1 °, and the analysis depth at this time is theoretically 2.1 μm from the surface.
Fluoride on the order of μm is thickened on the surface of the electroless nickel plating .

[Procedure amendment 9]

[Document name to be amended] Statement

[Correction target item name] 0039

[Correction method] Change

[Correction contents]

FIG. 9 shows the result of analyzing the test piece of Example 4 by AES. The elements detected on the surface were as described in Example 3 above.
Similarly to the above, there were four elements of Ni, F, O and C. Table 2 shows the element composition in the outermost layer. Water adsorbed to the surface, C is as due to dirt, O is removed by argon ion sputtering for a few minutes, became not detected. The atomic ratio of Ni to F was about 1: 2, and the formation of nickel fluoride (NiF ₂ ) on the outermost layer was recognized in combination with the analysis result of the X-ray diffraction analysis described above. Argon ion sputtering was further performed, and there was no significant change in the surface condition even after 280 minutes, and it was confirmed from the etching rate of argon ion sputtering that the film thickness (in terms of SiO ₂ ) was 3.2 μm or more and the film was thickened. Was.

[Procedure amendment 10]

[Document name to be amended] Statement

[Correction target item name] 0041

[Correction method] Change

[Correction contents]

FIG. 10 shows the result of analyzing the test piece of Comparative Example 1 by AES. The elements detected on the surface are Ni, F,
There were four elements, O and C. Table 3 shows an element composition table of the outermost layer. Water adsorbed to the surface, C is as due to dirt, O is removed by argon ion sputtering of about 1 minutes, but not detected. Although the atomic ratio of Ni to F was about 1: 2, the detection intensity of fluorine began to decrease in a few minutes from the start of sputtering, and was stopped in about 20 minutes. The etching rate of argon ion sputtering is 115 angstroms /
(Correction of SiO ₂ ), the film thickness including the fluorine diffusion layer was 2300 angstroms, and it was confirmed that the formed film was a sub-μm-order fluoride film.

[Procedure amendment 11]

[Document name to be amended] Statement

[Correction target item name] 0043

[Correction method] Change

[Correction contents]

Effect Example 1 Table 4 shows the results of conducting corrosion resistance tests on various materials. The corrosion resistance evaluation test was carried out at room temperature (25%
° C) It was represented by the weight loss of various materials when immersed for 24 hours. The surface-treated test pieces formed in Production Examples 2 and 3 and the test pieces of Examples 3, 4, 5, and 6 were used as comparative materials. As a result of measuring and comparing the weight loss when taken out after 24 hours, Example 5 had the least weight loss. Example 3 shows the change in appearance.
In No. 5, pitting occurred on the edge of the test piece, etc. Except for this point, the weight loss was smaller in each of the examples than in the electroless nickel plated test pieces of Production Examples 2 and 3. . This indicated that the test piece having a fluoride formed on the surface was extremely excellent in corrosion resistance.

[Procedure amendment 12]

[Document name to be amended] Statement

[Correction target item name] 0052

[Correction method] Change

[Correction contents]

[0052]

The thick fluorinated layer achieved by the present invention is excellent in acid resistance and alkali resistance, and is extremely effective as a device member mainly for semiconductor-related equipment. Therefore, a metal material or a metal film having a surface fluorinated layer formed according to the present invention is extremely effective as a device for manufacturing a semiconductor device or a device member of a vacuum-related device.

[Procedure amendment 13]

[Document name to be amended] Statement

[Correction target item name] Brief description of drawings

[Correction method] Change

[Correction contents]

[Brief description of the drawings]

FIG. 1 is a chart showing XPS spectrum measurement results of Example 4.

FIG. 2 is a chart showing an analysis result by the XDF thin film method of Production Example 1.

FIG. 3 is a chart showing an analysis result by an XDF thin film method of Production Example 2.

FIG. 4 is a chart showing an analysis result by the XDF thin film method of Production Example 3.

FIG. 5 is a chart showing an analysis result by the XDF thin film method of Example 2.

FIG. 6 is a chart showing an analysis result by the XDF thin film method of Example 4.

FIG. 7 is a chart showing an analysis result by the XDF thin film method of Example 6.

FIG. 8 is a chart showing a measurement result of a surface composition by AES in Example 3.

FIG. 9 is a chart showing a result of measurement of a fluoride film by AES in Example 4.

FIG. 10 is a chart obtained by analyzing a test piece of Comparative Example 1 by AES.

FIG. 11 is a table (Table 5) showing the results of performing a corrosion resistance test on the test pieces of Production Examples 2 and 3.

FIG. 12 is a graph showing measurement results of a natural oxide film of an Al alloy material and an oxide film AES formed by vapor phase oxidation.

FIG. 13 is a graph showing measurement results of a native oxide film of Cu metal and an oxide film AES formed by vapor phase oxidation.

FIG. 14 is a graph showing measurement results by an oxide film AES by gas phase oxidation and liquid phase oxidation of a NiP film.

──────────────────────────────────────────────────続 き Continuation of front page (51) Int.Cl. ⁶ Identification code FI C23C 8/42 C23C 8/42 (72) Inventor Satoshi Hirano 5-1 Ogimachi, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture Showa Denko Corporation Kawasaki Plant Inside

Claims (11)

[Claims] 1. A metal material or a metal film having a fluorinated surface layer, wherein a fluorinated layer having a thickness of 1 μm or more is formed on the surface of the metal material or the metal film after forced oxidation of the surface. 2. The metal film having a fluorinated surface layer according to claim 1, wherein the metal film comprises a nickel film on a substrate. 3. The fluorine-containing layer according to claim 1, wherein said fluoride layer comprises a first layer substantially composed of a fluoride of said nickel film and a second layer in which fluorine is diffused in a lower layer of said first layer. Metal film having a surface layer. 4. A method for fluorinating a metal material or a metal film, wherein the metal material or the metal film is forcibly oxidized with an oxidizing substance, and the forced oxide film is reacted with a fluorinated gas. 5. The method according to claim 4, wherein the metal material is aluminum or an aluminum alloy. 6. The method according to claim 4, wherein the metal material is copper or a copper alloy. 7. The method according to claim 4, wherein the metal film is a film formed by electrolytic or electroless plating of nickel or a nickel alloy. 8. The method according to claim 4, wherein the oxidizing substance is at least one of oxygen, nitrous oxide, nitrous oxide, ozone, and a mixed gas containing these gases.
The method for fluorinating a metal material or a metal film according to the above item. 9. The method for fluorinating a metal material or metal film according to claim 4, wherein the oxidizing substance is a solution containing nitric acid or a hydrogen peroxide solution. 10. The method according to claim 4, wherein the oxidizing substance is oxygen generated at the anode by an anodic oxidation method.
The method for fluorinating a metal material or a metal film according to the above item. 11. The fluorinated gas is fluorine (F ₂ ),
5. A gas which is at least one gas selected from the group consisting of chlorine trifluoride (ClF ₃ ) and nitrogen fluoride (NF ₃ ), or a gas obtained by diluting this gas with an inert gas.
11. The method for fluorinating a metal material or a metal film according to any one of items 1 to 10.