JP2867376B2 - Metal material having fluorinated passivation film formed thereon, gas apparatus using the metal material, and method of forming fluorinated passivation film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a metal material having a passivation film mainly composed of nickel, aluminum and copper fluorides formed on the surface thereof.
The present invention relates to a device using the same and a method for forming a passivation film thereof, and more particularly, to a metal material having significantly improved corrosion resistance, and a device using the same, which is intended for a technical field using a high-purity gas. The present invention is to provide an extremely effective metal material in the above.

[Prior art and its problems] The semiconductor manufacturing process uses a special gas having a high reactivity and corrosiveness, for example, BCl ₃ , SiF ₄ , WF _6. Strongly corrosive acids such as sulfur and hydrogen fluoride are generated. Usually, even if a metal material is used for a storage container, a pipe, a reaction chamber, or the like that handles these gases, it is easily corroded and has many problems.

In recent years, the size of unit elements of semiconductor devices has been reduced year by year in order to improve the degree of integration, and research and development are being carried out for practical use of semiconductor devices having a size of 1 μm to submicron, and further, 0.5 μm or less. .

As the degree of integration is improved and a low-temperature manufacturing process and a process with high selectivity are indispensable, high cleanliness of the process atmosphere is required, and some corrosion occurs in equipment requiring such cleaning. The generated impurities are mixed into the wafer to deteriorate the film quality and the like, so that the precision of the fine processing cannot be obtained and serious deterioration occurs in the reliability indispensable for ultra-fine and ultra-highly integrated devices. Therefore, it is indispensable to prevent corrosion of the metal surface.However, the conventional equipment does not take measures against corrosiveness of the inner surface of the gas supply device, and secondary measures are taken due to the strong reactivity of the halogen-based special gas used. Pollution has occurred and the ultra-high purity of the gas has not been achieved, which has hindered technological progress.

In the field of excimer lasers, laser oscillators are corroded by fluorine and cannot be used for a long period of time, and their practical use is delayed.

Devices that handle halogen-based special gases, such as RIE,
If the passivation treatment is not performed in the equipment such as CVD and / or cylinder and piping, the following reaction occurs between the gas used and the oxide film on the metal surface or the moisture adsorbed on the metal surface. As a result, by-product gas causes secondary pollution.

It is known that BF ₃ gas decomposes with moisture by the following reaction.

BF ₃ + 3H ₂ O → B (OFH ₂ ) ₃ For this reason, when filling the cylinder with BF ₃ gas, it is necessary to repeat the filling and withdrawal of the BF ₃ gas several times in order to remove non-water adhering in the cylinder, and then clean the inside. That is the current situation.

In addition, the confirmation of the by-products in the above-mentioned reaction was carried out by filling a halogen-containing special gas into a cylinder adsorbing moisture or analyzing an infrared absorption spectrum of the gas passing through a pipe adsorbing moisture. .

For this purpose, it has been studied to perform a corrosion resistance treatment on a metal surface. One of the studies is a study on fluorination of a metal surface, and the studies performed so far are as follows.

For example, (1) Reaction of fluorine with a nickel surface as described in ANL-5924, page 42 (1958).

(2) Fluorine reaction with nickel surface as described in ANL-6467, page 122 (1961).

(3) Reaction of nickel surface with fluorine as described in J. Electrochem. Soc. 110, pp. 346 (1963). (4) As described in Matheson Gas Date Book. How to make a dynamic film.

(5) As described in Ind. Eng. Chem. 57, 47 (1965), a nickel alloy is fluorinated at room temperature, and a study of metal corrosion in liquid fluorine thereof.

(6) A study in which the reaction rate between iron and fluorine was determined as described in J. Electrochem. Soc. 114, 218 (1967).

(7) As described in Trans. Met. Soc. AIME Vol. 242, pp. 1635 (1968), a passive film formation reaction of nickel and copper alloys with fluorine at normal temperature.

(8) Research on fluorination of copper and iron as described in Oxid. Metals. 2, p. 319 (1970).

(9) A study for determining the fluorination reaction rate of iron having an electropolished surface as described in Oxid. Metals. 4, p. 141 (1972).

Etc. are known. A few explanations about these known studies are added.

That is, in (1), (2) and (3), only the reactivity of nickel is described, and the corrosion resistance of the formed film is not described. Further, (4) and (5) show that the film is not positively formed but fluorinated at room temperature, and the corrosion resistance is not described in detail. (6) describes the reaction mechanism of iron. (7) describes the corrosion resistance of the formed passivation film, but both the film formation conditions and the corrosion resistance test are as low as 27 ° C., and the film thickness is too small to be practical. Further, (8) and (9) describe the fluorination conditions of iron and copper,
Although iron has good corrosion resistance at 200 ° C, it was evaluated only for the peeling limit temperature during the film formation process, not for the corrosive gas.

That is, the above report is only a study of the fluorine reaction, and does not include the formation of a practical fluorinated passivation film.
Accordingly, there is a strong demand for the formation of a fluorinated passivation film that can be expected to have complete corrosion resistance under severe conditions.

[Problem to be Solved by the Invention] The problem to be solved by the present invention is to form a fluorinated passivation film of a metal containing at least one of nickel, aluminum, copper and chromium on the surface of a base material. It is an object of the present invention to prevent the purity of a purity gas from lowering and to use a metal material having sufficient corrosion resistance to corrosive gases such as special gases.

[Means for Solving the Problems] The object of the present invention is to form a fluoride passivation film having a metal fluoride composed of at least one of nickel, aluminum and copper as a main component on a surface of a metal material. The problem is solved by using this in a gas device.

That is, as a result of repeated research on the corrosiveness of the metal surface, the present inventors have found that a base having a surface made of a metal containing at least one of nickel, aluminum, copper, and chromium is baked as necessary, Fluorine is positively acted on the metal surface at a temperature sufficient for fluorination to form a film containing the above-mentioned metal fluoride as a main component, and then the film is exposed to an inert gas atmosphere and subjected to a heat treatment to cause corrosion. It has been found that a fluorinated passivation film having good corrosion resistance to an inert gas can be formed.

More specifically, after baking a substrate having a mirror-finished surface, heating to a sufficient temperature at which fluorination occurs, fluorine alone, or Nz, Ar, diluted with an inert gas such as He and allowed to act, After forming a film of about 200 ° or more containing metal fluoride as a main component that has good adhesion to metal and does not cause peeling, the film is exposed to an inert gas atmosphere and subjected to a heat treatment to form a fluorine-free film. A dynamic film is formed. The formed fluorinated passivation film was found to exhibit extremely excellent corrosion resistance to corrosion-resistant gases, and the present invention has been completed based on this.

[Structure and Function of the Invention] The present invention basically comprises nickel, aluminum,
Forming a fluorinated passivation film on the surface of a substrate made of a metal containing at least one of copper and chromium.

As the substrate used in the present invention, a substrate whose surface is made of a metal containing at least one of nickel, aluminum, copper and chromium is used. In addition, any of a wide range of materials in which the metal film is formed on the surface of the base material by a suitable means such as plating vacuum evaporation or sputtering can be used. A material containing at least one of the above metals in an amount of 50% by weight or more is used as the surface of the substrate.

In the present invention, the base material is baked in an inert gas, if necessary, and then fluorinated, and at least part of the surface, or the entire surface, is exposed to a fluorine-containing atmosphere, and subjected to a thermal film-forming treatment. A fluoride film made of metal fluoride is formed, and heat treatment is performed again in an atmosphere of an inert gas. The baking temperature is 350 to 600 ° C, preferably 400 to 500 ° C when nickel, copper and chromium are the main components. The baking time is 1 to 5 hours. Baking temperature is 35
If the temperature is lower than 0 ° C., the moisture adhering to the surface is not completely removed, and when fluorination is performed in such a state, the formed fluorinated passivation film does not become completely fluorinated passivated satisfying the stoichiometric ratio. . When aluminum is the main component, the baking temperature is 150 to 400 ° C, preferably 200 to 300 ° C. The baking time is 1 to 5 hours. The fluorination temperature is 200 for nickel, copper and chromium as main components.
-500 ° C, preferably 250-450 ° C. The fluorination time is 1 to 5 hours. If the fluorination temperature is lower than 200 ° C., a fluorinated passivation film having a sufficient thickness and excellent corrosion resistance cannot be obtained. Further, when fluorination is performed at a temperature higher than 450 ° C., the crystal grain boundaries of the fluoride are formed in the formed fluorinated passivation film, which causes cracks and peeling. Hastelloy C has a fluorination temperature of 150
-300 ° C, preferably 150-250 ° C. When fluorinated at a temperature higher than 300 ° C., peeling occurs and a fluorinated passivation film having excellent corrosion resistance cannot be obtained. When aluminum is the main component, the fluorination temperature is 200 to 400 ° C, preferably 250 to 3 ° C.
50 ° C. When fluorinated at a temperature higher than 350 ° C., crystal grains of aluminum fluoride are formed in the formed fluorinated passivation film, and cracks and peeling occur.

The fluorination is basically performed by exposing to a fluorine-containing atmosphere to perform a thermal film formation process, and is performed under normal pressure. However, the fluorination can be performed under pressure if necessary. The pressure at this time may be about 2 atm or less in gauge pressure. The fluorination atmosphere is preferably carried out in the absence of oxygen, so that fluorine alone or a suitable inert gas such as N ₂ , Ar,
It is preferable to use it after dilution with He or the like. X-ray diffraction analysis of a passivated nickel film formed below 450 ° C
Surface Science Instruments' despite being NiF ₂
The ratio of the analyzed at Products Co. bias SSX-100 type ESCA Ni and F is approximately 1.1 times the stoichiometric ratio of NiF _2. That is, the amount of fluorine relative to nickel is about 1.1 times in excess, but this excess fluorine is present in the passivation film in a free state without bonding with nickel. Since this excess amount impairs corrosion resistance, it cannot be a corrosion-resistant material.
All passivation films reported hitherto are passivation films containing this excess fluorine and have no corrosion resistance. The heat treatment in the present invention is basically performed by exposing to an inert gas atmosphere, and when nickel, copper, and chromium are the main components, 300 to 600 ° C., preferably 400 to 500 ° C. It is. When aluminum is the main component, the temperature is 200 to 400 ° C, preferably 250 to 400 ° C. This heat treatment is performed after the fluorination step, but may be performed continuously with the fluorination. In this case, the steps of the heat treatment and the fluorination may be partially overlapped. By performing this heat treatment in an inert gas such as N ₂ , Ar, or He for 1 to 5 hours,
It forms a fluorinated passivation film that is robust, dense, has good adhesion to metal, and has sufficient corrosion resistance. It is a surprising phenomenon that the film quality of the passivation film is changed by the heat treatment, and it is a fact that has not yet been recognized. When the change in the film quality was examined by ESCA, the ratio between the metal element and the fluorine in the fluorinated passivation film satisfied the stoichiometric ratio after the heat treatment. The thickness of the passivation film containing nickel fluoride as a main component was measured using an AEP-100 type ellipsometer manufactured by Shimadzu Corporation.

As one embodiment of performing the fluorination and heat treatment of the present invention, there is a mode in which the surface of the metal is exposed to a fluorine atmosphere while heating the substrate, and then exposed to an inert gas atmosphere.

In the present invention, when performing the above fluorination, it is preferable to previously smooth the surface of the substrate to be fluorinated. At this time, the smoothness is Rmax = 0.03 to 1.0 μm
It is preferable that the surface is mirror-finished to about (the maximum value of the difference between surface irregularities), and according to the study of the present inventors, Rmax = 0.
It has been found that the fluoride passivation film formed on the mirror-finished metal surface up to about 03 to 1.0 μm has significantly improved corrosion resistance over the fluoride passivation film formed on the non-mirror metal surface. ing. At this time, the mirror finishing means itself is not limited at all, and an appropriate means is selected in a wide range, and a representative example thereof is a means by complex electrolytic polishing.

The fluorinated passivation film thus formed is usually formed in a thickness of 200 mm or more, preferably 300 mm or more, and is not easily peeled off because it is formed with sufficient strength on the metal as the base material, and almost no cracks are generated. There is no passive film.

 Next, the gas device of the present invention will be described.

The gas device of the present invention basically uses a metal material having the above-mentioned fluorinated passivation film formed on a portion which comes into contact with a gas, particularly a corrosive gas, and further uses the above-mentioned metal on a portion which does not come into contact with the corrosive gas. Of course, it may be possible. Also,
The passivation film may be formed directly on a necessary part of the gas device.

The present inventors have studied the corrosion resistance of the apparatus to the halogen-based special gas and the contamination of the high-purity gas, and as a result, by forming a metal fluoride passivation film with fluorine gas on the metal surface inside the apparatus, the apparatus has been developed. The inventors have found that they have corrosion resistance to halogen-based special gases and do not contaminate high-purity halogen-based special gases, and have completed the invention relating to the apparatus.

As a gas device, it is used as a broad concept encompassing all devices that handle gas, for example, for gas storage,
Alternatively, a gas delivery apparatus, a reaction apparatus that uses a gas or generates a gas, and the like can be exemplified. More specifically, for example, cylinders, gases, holders, piping, valves, RIE
It is a reactor, a CVD reactor, an excimer laser oscillator or the like.

FIG. 1 is a schematic diagram showing an example of a gas device. The apparatus includes a gas storage cylinder 201, a gas supply system 202 including a valve, a mass flow controller, and the like, a reaction apparatus 203 including a RIE apparatus, a CVD apparatus, and the like, and an evacuation apparatus 20.
Consists of five. A passive film 204 is formed on the inner wall of the chamber of the reaction device 203.

FIG. 2 is a schematic view showing an example of passivating the inner wall of the reaction chamber. When the reaction chamber 303 is passivated, N _{2 of} ultra-high purity from the gas introduction line 301 introduces Ar into the reaction chamber at, for example, about 10 per minute.
Drain the water by mixing. Whether the drainage is sufficient or not depends on the dew point meter 3
You can do this by monitoring the pargas open at 05. Thereafter, the entire chamber 303 is further heated to about 400 to 500 ° C. by the electric furnace 302 to desorb H ₂ O molecules almost completely adsorbed on the inner surface.

Next, high-purity F ₂ is introduced into the chamber, and the inner surface of the chamber is fluorinated. After performing fluorination for a predetermined time, ultra-high purity N ₂ or Ar is again introduced into the chamber to purify the high-purity F ₂ remaining in the chamber. After the completion of the purging, heat treatment is performed on the passivation film formed on the inner wall of the chamber while flowing ultra-high purity N ₂ or Ar as it is. The fluorinated passivation film thus formed is extremely stable against corrosive gases.

The gas used for this gas device is nitrogen, argon,
Inert gas such as helium and halogen-based gas, for example,
_{F 2, Cl 2, NF 3} , CF 4, SF 4, SF 6, SiF 4, BF 3, HF, WF 6, M
oF ₆ , PF ₃ , PF ₅ , AsF ₃ , AsF ₅ , BCl _{3 and the} like. When fabricating a device using the metal having the fluorinated passivation film, the device may be fabricated using a metal on which the fluorinated passivation film is formed in advance. Fluorine may be applied to the constituent metal to form a fluorinated passivation film. The conditions for the fluorination at this time may be performed under the conditions described above.

[Examples] In order to clarify the technical contents of the present invention, representative examples are extracted and illustrated below as examples.

Example 1 A nickel polished plate (both flatness Rmax = 0.03 to 1.0 μm) and a SUS-316L substrate on which nickel was deposited to a thickness of 4000 ° by sputtering were baked at 500 ° C. for 1 hour in high-purity N ₂ gas at 100% F. After fluorination with ₂ gases for 1 to 5 hours, heat treatment was performed at 500 ° C. for 2 hours in an inert gas. Table 1 shows the results of the film thickness at each temperature during the fluorination. The film formed by fluorinating the nickel polished plate and the nickel deposited by sputtering at each temperature did not show any crystal grain boundaries, cracks or peeling.

Example 2 A Hastelloy C (Ni51, Mo19, Cr17, Fe6, W5) polished plate (both flatness Rmax = 0.03 to 1.0 μm) was placed in a high-purity N ₂ gas for 5 hours.
After baking at 00 ° C. for 1 hour, it was fluorinated with 100% F ₂ gas for 1 to 5 hours, and then heat-treated at 400 ° C. for 2 hours in an inert gas. Table 2 shows the results of the film thickness at each temperature during fluorination.
No cracking and peeling were observed in the film formed by fluorination at 200 and 250 ° C.

Example 3 Monel (Ni66, Cu29, Al3) polished plate (both flatness Rmax =
0.03 to 1.0 μm) was baked in high-purity N ₂ gas at 500 ° C. for 1 hour and then fluorinated with 100% F ₂ gas for 1 to 5 hours.
Table 3 shows the results of the film thickness at each temperature during the fluorination. When the fluorination temperature was 500 ° C., slight color unevenness was observed on the surface of the passive film, but no cracks or peeling were observed.

Example 4 Copper polished plate (both flatness Rmax = 0.03 to 1.0 µm) and SUS-
500 ° C. The surface was 4000Å deposited copper by sputtering 316L substrate with high purity N ₂ gas, 500 ° C. in an inert gas after allowed 1-5 hours fluorinated with 1 hour baking after 100% F ₂ gas,
Heat treatment was performed for 2 hours. Table 4 shows the results of the film thickness at each temperature during the fluorination. Cracking and peeling of the passive film were not observed in both the copper polishing plate and the copper deposited by sputtering.

Example 5 A surface of SUS-316L substrate on which chromium was deposited to a thickness of 4000 mm by sputtering was baked in high-purity N ₂ gas at 500 ° C. for 1 hour and then baked.
After fluorination with 00% F ₂ gas for 1 to 5 hours, heat treatment was performed at 500 ° C. for 2 hours in an inert gas. Table 5 shows the results of the film thickness at each temperature during the fluorination. At any temperature, no cracking or peeling of the passive film was observed at all.

Example 6 Polishing plate of aluminum and aluminum alloy (both flatness
Rmax = 0.03 ~ 1.0μm) and the surface of SUS-316L substrate with 2000mm of aluminum formed by sputtering is baked in high purity N ₂ gas at 300 ℃ for 1 hour, then fluorinated with 100% F ₂ gas for 1-5 hours. After that, heat treatment was performed at 350 ° C. for 2 hours in an inert gas. Table showing the results of film thickness at each temperature during fluorination.
6 is shown. In the films formed by fluorination at 250 ° C. and 300 ° C. for both aluminum, aluminum alloys and aluminum deposited by sputtering, no crystal grain boundaries, cracks or peeling of aluminum fluoride were observed.

Example 7 When a nickel polished plate (both flatness Rmax = 0.03 to 1.0 μm) was baked in high-purity N ₂ gas at 500 ° C. for 1 hour and then fluorinated in 100% F ₂ gas at 350 ° C. for 1 to 5 hours. FIG. 3 shows an ESCA chart of the nickel surface, and FIG. 4 shows an ESCA chart when the nickel plate on which the fluoride film was formed was further heat-treated at 400 ° C. for 2 hours in high-purity N ₂ gas. The average of the atomic ratios of Ni and F in FIG.
The average of the atomic ratios is 3.34. That is, it can be seen that (1.11) times excess fluorine exists in the fluoride film before the heat treatment. The ratio of the heat treatment was 3.34, which did not match the chemical structure NiF ₂ of the fluorinated passivation film determined by X-ray diffraction, but this difference was because the ESCA was not calibrated. It is clear that the improvement of the composition ratio in FIGS. 3 and 4 is due to the effect of the heat treatment.

Example 8 Monel (Ni66, Cu29, Al3) polished plate (both flatness Rmax =
0.03 to 1.0 μm) in high purity N ₂ gas at 500 ° C for 1 hour, then fluorinated in 100% F ₂ gas at 400 ° C for 1 to 5 hours to form a fluoride film, and then in high purity N ₂ gas FIG. 5 shows a chart of ESCA after heat treatment at 500 ° C. for 2 hours.

Example 9 Aluminum (5 # 1050) polished plate (both flatness Rmax = 0.
03-1.0 μm) in high-purity N ₂ gas at 300 ° C. for 1 hour, fluorinated in 100% F ₂ gas at 250 ° C. for 1-5 hours to form a fluoride film, and then in high-purity N ₂ gas FIG. 6 shows a chart of ESCA after heat treatment at 350 ° C. for 2 hours.

Example 10 A nickel polished plate (both flatness Rmax = 0.03 to 1.0 μm) was baked at 350 ° C. for 1 hour in a high-purity N ₂ gas and then fluorinated at 350 ° C. for 1 to 5 hours in 100% F ₂ gas for 1 to 5 hours. X after heat treatment at 400 ° C for 2 hours in high purity N ₂ gas after film formation
A line diffraction chart is shown in Fig. 7. A similar nickel polished plate was baked in high-purity N ₂ gas at 400 ° C for 1 hour and then fluorinated in 100% F ₂ gas at 350 ° C for 1 to 5 hours to form a fluoride film. And then heat treated again in high purity N ₂ gas at 400 ° C for 2 hours.
The line diffraction chart is shown in FIG. The X-ray chart when baked at 350 ° C. shows a peak of NiF ₂ .4H ₂ O, but when baked at 400 ° C., only the NiF ₂ peak is detected. The fluoride film on which NiF ₂ .4H ₂ O is formed as shown in FIG. 7 is cracked and peeled off, so that a passive film having excellent corrosion resistance cannot be obtained.

Example 11 A Hastelloy C (Ni51, Mo19, Cr17, Fe6, W5) polished plate (both flatness Rmax = 0.03 to 1.0 μm) was placed in a high-purity N ₂ gas for 5 hours.
00 ° C, baking for 1 hour, 250 ° C in 100% F ₂ gas, 1 ~
FIG. 9 shows an X-ray diffraction chart obtained after fluorinating for 5 hours and forming a fluorinated film, followed by heat treatment at 400 ° C. for 2 hours in high-purity N ₂ gas.

Example 12 A copper polished plate (both flatness Rmax = 0.03 to 1.0 µm) was
500 ° C. ₂ gas, 4 100% F ₂ gas after 1 hour Baking
FIG. 10 shows an X-ray diffraction chart when the film was fluorinated at 00 ° C. for 1 to 5 hours to form a fluorinated film and then heat-treated at 500 ° C. for 2 hours in high-purity N ₂ gas. A sharp peak of CuF ₂ is obtained.

Example 13 The surface of SUS-316L substrate on which chromium was deposited to a thickness of 4000 mm by sputtering was baked in high-purity N ₂ gas at 500 ° C. for 1 hour, and
FIG. 11 shows an X-ray diffraction chart obtained when the film was fluorinated with 00% F ₂ gas for 1 to 5 hours to form a fluorinated film and then heat-treated at 500 ° C. for 2 hours in a high-purity gas. A sharp peak of CuF ₂ is obtained.

Example 14 Table 7 shows the evaluation of the corrosion resistance of the fluorinated passivation film using the most corrosive and permeable chlorine gas. The evaluation was performed by filling chlorine gas at atmospheric pressure in a 1 / 4-inch diameter nickel electrolytic polishing tube with a different thickness of the passivation film, immediately after sealing at 100 ° C for 1 hour, and inside the tube after leaving for 1 hour. The reaction amount of the gas was calculated from the pressure difference. Figure 12 shows a schematic diagram of the equipment used for evaluation. When the film thickness was about 200 mm or more, the corrosion resistance was excellent when heat-treated.

Example 15 Table 8 shows the evaluation of the corrosion resistance of the fluorinated passivation film using a hydrogen fluoride gas containing water that significantly promotes the corrosiveness. For evaluation, test pieces having different thicknesses of the passivation film were sealed in a composition gas shown below at 25 ° C. for 14 days, and the degree of corrosion of the passivation film surface was examined. Each sample had a thickness of about 200 ° or more, and no corrosion was observed when heat treatment was performed.

Sealed gas composition (vo1%) HF: 5 H 2 O: 2.5 N 2: 92.5 Example 16 Brass (Cu70, Zn30) polishing plate (both flatness Rmax = 0.03 to 1.
0μm) after baking in high purity N ₂ gas at 300 ℃ for 1 hour
After fluorination for 1 to 5 hours with 100% F ₂ gas, heat treatment was performed at 350 ° C. for 2 hours in an inert gas. Table 9 shows the results of the film thickness at each temperature during the fluorination. No cracking or peeling of the passive film was observed at any temperature.

[Effect of the Invention] The fluorinated passivation film formed according to the present invention was found to have strong corrosiveness and remarkable corrosion resistance to halogen-based gases. It was recognized that the metal material on which the fluorinated passivation film was formed was very effective for the fabrication of VLSI microfabrication equipment. That is, it is possible to supply an active gas such as F ₂ and HF which could not be handled at all with the conventional technology. As a result, the natural oxide film on Si wafers, which could only be removed by a wet process using a liquid, can now be removed with HF gas. It has contributed crucially to higher process performance, such as lowering the process temperature and improving selectivity due to differences in the base material.
Further, as an excitation light source for various photoexcited chemical reactions, or
As a light source for excimer laser steppers, which is promising as an ULSI dew device with a pattern size of 0.5 microns or less,
The technology of the present invention is most suitable for excimer lasers for which high reliability and long life are desired. The emission wavelengths of the KrF excimer laser and the ArF excimer laser are 248 nm,
193 nm. Submicron U for photochemical reaction excitation
This is the perfect wavelength for LSI exposure. However, the conventional excimer laser could not be a practical technique because the output fluctuation per pulse exceeded 10% and the lifetime was only 1 million pulses.

A gas supply system in which the fluorinated passivation film of the present invention is applied to the inner surface,
In addition, the fluctuation of each pulse of the excimer laser (ArF, KrF) using an electrode provided with a fluoride passivation film on the surface was within 1%, and the life was improved to 10 million pulses. It can be used as a stepper for one year with one shot exposure per second. It has been improved to the point where it can completely withstand practical technology.

The present inventors have separately invented the technique of the fluorinated passivation film according to the present invention as a “dry etching apparatus” (July 20, 1988).
And "Anhydrous hydrogen fluoride dilution gas generator"
By using this method (filed on July 20, 1988), high-purity hydrogen fluoride gas can be supplied, and the corrosion resistance of the apparatus has been extremely improved.

[Brief description of the drawings]

FIG. 1 is a schematic view of a gas apparatus showing one embodiment of the present invention. FIG. 2 is a schematic view showing an example of a method for fluorinating a reaction chamber. Figure 3 is 500 ° C. with high purity N ₂ gas, 1
FIG. 4 is an ESCA chart of a nickel surface when fluorinated at 350 ° C. for 1 to 5 hours with 100% F ₂ gas after baking for 1 hour. FIG. 4 shows baking at 500 ° C. for 1 hour in high-purity N ₂ gas, and then fluorinating with 100% F ₂ gas at 350 ° C. for 1 to 5 hours.
FIG. 4 is an ESCA chart of the nickel surface when heat treatment is further performed at 400 ° C. for 2 hours with high-purity N ₂ gas. Figure 5 is 500 ° C. with high purity N ₂ gas at 100% F ₂ gas was baked 1 hour 40
0 ° C., after 1-5 hours fluorination, further in high purity N ₂ gas 500
FIG. 4 is an ESCA chart of the surface of Monel after heat treatment at 2 ° C. for 2 hours. Figure 6 is 300 ° C. with high purity N ₂ gas, 250 ° C. at 100F ₂ gas was baked for 1 hour, after 5 hours fluorination, further 350 ° C. with high purity N ₂ gas, when heat-treated for 2 hours FIG. 3 is an ESCA chart of the aluminum surface of FIG. Fig. 7 shows 100% after baking for 1 hour at 350 ° C in high purity N ₂ gas.
Fluorination at 350 ° C for 1-5 hours with F ₂ gas, and further high purity N ₂
4 is an X-ray diffraction chart of a fluorinated passivation film of a nickel polished plate after heat treatment at 400 ° C. for 2 hours in a gas. Fig. 8 shows 100% after baking at 400 ℃ for 1 hour in high purity N ₂ gas.
Fluorination at 350 ° C for 1-5 hours with F ₂ gas, and further high purity N ₂
4 is an X-ray diffraction chart of a fluorinated passivation film of a nickel polished plate after heat treatment at 400 ° C. for 2 hours in a gas. Fig. 9 shows 100% after baking for 1 hour at 500 ℃ in high purity N ₂ gas.
After fluorination with F ₂ gas at 250 ° C for 1 to 5 hours, further high purity N ₂
4 is an X-ray diffraction chart of the surface of Hastelloy C when heat-treated at 400 ° C. for 2 hours in a gas. Figure 10 is 500 ° C. with high purity N ₂ gas, 400 100F ₂ gas was baked 1 hour
° C., then 1-5 hours fluorination, further in high purity N ₂ gas 500
4 is an X-ray diffraction chart of a fluorinated passivation film of a copper polished plate after heat treatment at 2 ° C. for 2 hours. Figure 11 is a high-purity N ₂ gas 50
0 ° C., 400 ° C. at 100% F ₂ gas was baked 1 hour, 1
Fluorination for 5 to 5 hours, and then at 500 ° C in high-purity N ₂ gas.
4 is an X-ray diffraction chart of a fluorinated passivation film of sputtered chromium when heat-treated for an hour. FIG. 12 is an explanatory diagram of an apparatus used for evaluating a passive film shown in Example 14. 201 ... Gas cylinder 202 ... Gas supply system 203 ... Reaction chamber 204 ... Fluoride passivated membrane 205 ... Exhaust device 301 ... Gas introduction line 302 ... Electric furnace 303 ... Reaction chamber 304 ... Gas barge line 305: Dew point meter 401: Nickel 1/4 inch diameter electrolytic polishing tube 402: Heating device (direct current heating method) 403: Mercury manometer 404: Sample gas cylinder

Continuation of the front page (56) References JP 2-39586 (JP, B2) (58) Field surveyed (Int. Cl. ⁶ , DB name) C23C 8/08

Claims (37)

(57) [Claims] 1. A metal material having a metal base and a fluorinated passivation film made of nickel fluoride on the surface thereof, wherein the fluorinated passivation film has a sufficient amount to form a nickel fluoride film. After forming the nickel fluoride film in a fluorine-containing gas atmosphere at a temperature and time sufficient for forming the nickel fluoride film, the nickel fluoride film is formed in an inert gas atmosphere.
A metal material, which is a film obtained by performing a heat treatment at a temperature of 300 to 600 ° C. for 1 to 5 hours. 2. The metal material according to claim 1, wherein said nickel fluoride film has a thickness of 200 ° or more. 3. The metal material according to claim 1, wherein the metal substrate is baked in an inert gas atmosphere before forming the nickel fluoride film. 4. A gas apparatus having a portion in contact with a corrosive gas, wherein the portion in contact with the corrosive gas is sufficient to form a nickel fluoride film in a fluorine-containing gas atmosphere in an amount sufficient to form a nickel fluoride film. After forming the nickel fluoride film over various formation temperatures and times, the nickel fluoride film is subjected to a heat treatment at a temperature of 300 to 600 ° C. for 1 to 5 hours in an inert gas atmosphere. A gas device characterized by being coated with a passivation film. 5. The gas apparatus according to claim 4, wherein said nickel fluoride film has a thickness of 200 ° or more. 6. The gas apparatus according to claim 4, wherein a portion of the base material in contact with the corrosive gas is baked in an inert gas atmosphere before forming the nickel fluoride film. 7. A metal material having a metal substrate and a fluorinated passivation film made of aluminum fluoride on its surface,
The fluorinated passivation film, after forming the aluminum fluoride film in a fluorine-containing gas atmosphere in a sufficient amount of fluorine-containing gas atmosphere at a formation temperature and time sufficient to form the aluminum fluoride film, A metal material obtained by subjecting the aluminum fluoride film to a heat treatment at a temperature of 200 to 400 ° C. for 1 to 5 hours in an inert gas atmosphere. 8. The aluminum fluoride film has a thickness of 200 °.
The metal material according to claim 7, which is the above. 9. The metal material according to claim 7, wherein the metal material is baked in an inert gas atmosphere before forming the aluminum fluoride film. 10. A gas apparatus having a portion in contact with a corrosive gas, wherein the portion in contact with the corrosive gas forms an aluminum fluoride film in a fluorine-containing gas atmosphere in an amount sufficient to form an aluminum fluoride film. After forming an aluminum fluoride film over a sufficient formation temperature and time, the aluminum fluoride film is subjected to a heat treatment at a temperature of 200 to 400 ° C. for 1 to 5 hours in an inert gas atmosphere, A gas device characterized by being coated with a fluorinated passivation film. 11. The aluminum fluoride film has a thickness of 200
11. The gas device according to claim 10, which is not less than Å. 12. The base material in a portion in contact with the corrosive gas,
11. The gas device according to claim 10, wherein the gas device is baked in an inert gas atmosphere before forming the aluminum fluoride film. 13. A metal material having a metal base and a fluorinated passivation film made of copper fluoride on the surface thereof, wherein said fluorinated passivation film has a sufficient amount to form a copper fluoride film. After forming a copper fluoride film over a forming temperature and time sufficient for forming a copper fluoride film in a fluorine-containing gas atmosphere, the copper fluoride film is formed at a temperature of 300 to 600 ° C. in an inert gas atmosphere. A metal material, which is a film obtained by performing a heat treatment for 1 to 5 hours. 14. The metal material according to claim 13, wherein said copper fluoride film has a thickness of 200 ° or more. 15. The metal material according to claim 13, wherein the metal material is baked in an inert gas atmosphere before forming the copper fluoride film. 16. A gas apparatus having a portion in contact with a corrosive gas, wherein the portion in contact with the corrosive gas is used for forming a copper fluoride film in a fluorine-containing gas atmosphere in an amount sufficient for forming a copper fluoride film. After forming the copper fluoride film over a sufficient forming temperature and time, the copper fluoride film is
A gas device characterized by being coated with a fluorinated passivation film obtained by performing a heat treatment at a temperature of 600600 ° C. for 1 to 5 hours. 17. The gas device according to claim 16, wherein the thickness of the copper fluoride film is 200 ° or more. 18. The base material of the portion in contact with the corrosive gas,
17. The gas device according to claim 16, wherein the gas device is baked in an inert gas atmosphere before the formation of the copper fluoride film. 19. The gas device according to claim 4, wherein the gas device is a gas storage device, a gas delivery device, or a gas reaction device. 20. A gas system for handling corrosive gas, comprising: a gas cylinder, a gas holder, a gas pipe, a valve, and an RI.
17. The gas apparatus according to claim 4, which is an E reactor or a CVD reactor. 21. The gas device according to claim 4, wherein the gas device is an excimer laser oscillator. 22. The gas apparatus according to claim 20, wherein the corrosive gas is a halogen-based gas. 23. The halogen-based gas comprises F ₂ , Cl ₂ , NF ₃ , C
F ₄ , SF ₄ , SF ₆ , SiF ₄ , BF ₃ , HF, WF ₆ , MoF ₆ , PF ₃ , PF ₅ , AsF ₃ , AsF ₅ ,
Gas apparatus according to claim 22 is at least one in the BCl _3. 24. A surface of a substrate made of a metal containing at least one of nickel, aluminum, copper and chromium,
After applying a sufficient temperature and time to the formation of the metal fluoride, and exposing to a fluorine-containing atmosphere in an amount sufficient to form the metal fluoride, and subjecting the metal fluoride to thermal film formation,
Performing a heat treatment of exposing the metal fluoride to an inert gas atmosphere for 1 to 5 hours to form a fluorinated passivation film made of the metal fluoride, wherein the temperature of the heat treatment is nickel, copper, chromium, A method for forming a fluorinated passivation film, wherein the temperature is 300 to 600 ° C. for a metal containing at least one of the above, and 200 to 400 ° C. for a metal containing at least aluminum. 25. The method according to claim 24, wherein the thickness of the metal fluoride is 200 ° or more. 26. The method according to claim 24, wherein the base material is baked at 150 to 600 ° C. 27. A method for forming a fluorinated passivation film, comprising forming a fluoride film of a metal on a surface of a metal comprising at least one of nickel, aluminum, copper and chromium. Exposure to an atmosphere containing fluorine in an amount sufficient to form the fluoride of the metal while heating at a temperature and for a time sufficient for the formation of the fluoride of the metal, and then removing the fluoride of the metal with an inert gas. A step of exposing to an atmosphere for 1 to 5 hours, wherein the temperature at the time of exposing to the inert gas atmosphere is 300 to 600 ° C. for a metal containing at least one of nickel, copper and chromium, and a metal containing at least aluminum. Wherein the temperature is 200 to 400 ° C. 28. The method according to claim 28, wherein the thickness of the fluoride is 200 ° or more. 29. The method according to claim 27, wherein the substrate is baked at 150 to 600 ° C. 30. The substrate having a surface flatness of 0.03 to 1.0.
28. The method for forming a fluorinated passivation film according to claim 24, wherein the thickness is micron. 31. The method according to claim 24, wherein the fluorine-containing atmosphere is an atmosphere containing no or substantially no oxygen. 32. The method according to claim 24, wherein the inert gas is at least one of N ₂ , Ar, and He. 33. A fluorinating passivation treatment method inside a gas apparatus, wherein nickel, aluminum, copper,
A portion to be subjected to fluoridation passivation consisting of a metal containing at least one of chromium is placed in a fluorine-containing gas atmosphere in an amount sufficient for the formation of a fluoride film at a temperature sufficient for forming the fluoride film. Exposing the fluorinated film to an inert gas atmosphere for 1 to 5 hours, and then exposing the fluorinated film to an inert gas atmosphere at a temperature of at least one of nickel, copper, and chromium. A method for forming a fluorinated kinetic film in a gas apparatus, wherein the temperature is 300 to 600 ° C. and the temperature of a metal containing at least 200 to 400 ° C. 34. The method according to claim 33, wherein the thickness of the fluoride is 200 ° or more. 35. The method according to claim 33, wherein the fluorine-containing atmosphere is an atmosphere containing no or substantially no oxygen. 36. The method according to claim 33, wherein the inert gas is at least one of N ₂ , Ar, and He. 37. The method of claim 33, wherein the gas device is a gas cylinder, a gas holder, a gas pipe, a valve, an RIE reactor, a CVD reactor, or an excimer laser oscillator.