JP3115103B2 - Industrial material with fluorinated passivation film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an industrial material having a fluorinated passivation film formed on the surface of a metal, ceramics, plastics, or the like, and in particular, it is possible to remarkably improve the corrosion resistance to corrosive gases such as halogen gas. The present invention relates to an industrial material having a fluorinated passivation film formed thereon.

[0002]

2. Description of the Related Art Generally, in a semiconductor manufacturing process, a highly reactive and corrosive special gas such as BCl ₃ , SiF ₄ , WF ₆ , Cl ₂ or the like is used. If present, hydrolysis occurs, and a highly corrosive acid such as hydrogen chloride or hydrogen fluoride is generated. Therefore, even if aluminum or aluminum alloy products (hereinafter abbreviated as aluminum products) are used for storage containers, piping, reaction chambers, etc. that handle these gases,
There was a problem that it was easily corroded.

[0003] Various attempts have been made to prevent corrosion by the above gases. The present inventors have already formed a plating film composed of nickel, tungsten, and phosphorus on the surface of Al or an Al alloy, and formed a fluorinated passivation film containing no tungsten and phosphorus on at least the surface of the plating film. Such an invention was filed (Japanese Patent Application No. 2-283151).

[0004]

However, the fluorinated passivation film formed by the invention according to the above-mentioned application is characterized in that the nickel alloy thin film formed on the surface of the substrate is partially formed of a mixed phase of nickel and a nickel alloy. Therefore, the fluorinated passivation film formed cannot be a completely uniform film, and an ideal passivation film has not been formed.

The present invention has been made in view of the above points, and is intended to provide an industrial material which can significantly improve the corrosion resistance against corrosive gases and the like, and in particular, has a fluorinated passive film effective in the field of semiconductor manufacturing. The task is to provide.

[0006]

The object of the present invention is to provide a single phase (hereinafter referred to as a single phase) having a composition of nickel-tungsten-phosphorus and a structure of the nickel-tungsten-phosphorus on a surface of a substrate. An industrial material in which a nickel alloy thin film composed of nickel / tungsten / phosphorus) is formed and a fluorinated passivation film containing no tungsten / phosphorus is formed on at least the surface of the alloy thin film. The problem can be solved by setting the composition range of the nickel alloy thin film composed of the components to 5% or less of tungsten and 9% or more of phosphorus.

[0007]

It is a well-known fact that nickel-tungsten-phosphorous plating film originally has excellent corrosion resistance. The inventors of the present invention have already filed an application for the point that the fluorinated passivation film made of NiF ₂ formed on the surface of the tungsten-phosphorus plating film exhibits even better corrosion resistance (Japanese Patent Application No. 2-283).
No. 151).

However, as a result of further research conducted by the present inventors, the optimum ratio of each of the nickel, tungsten, and phosphorus plating films is set to be approximately single-phase, which exhibits remarkably excellent characteristics. It has been discovered that a fluorinated passivation film formed on a nickel-tungsten-phosphorus plating film can be formed.

That is, in the ordinary nickel-tungsten-phosphorous plating film, a film made of a mixed phase of nickel and a nickel alloy is formed by the process of fluorinating passivation treatment, and the fluoride film formed on such a mixed phase film is formed. Subsequent research by the present inventors has revealed that the passivation film becomes a non-uniform passivation film with grain boundaries, and is hardly an ideal passivation film.

The present inventors have attempted structural analysis by X-ray diffraction in order to form a fluorinated passivation film formed on an ideal single-phase film, and as a result, have found that the desired substantially single-phase nickel-tungsten In addition to establishing the conditions for forming a fluorinated passivation film formed on a phosphorous plating film, the fluorinated passivation film formed according to the present invention is the most excellent evaluation method for evaluating corrosion resistance. It was confirmed by a potential measurement method that it had much better performance than the conventional fluorinated passivation film.

The most important feature of the present invention is that the composition range of the nickel alloy thin film composed of substantially single-phase nickel-tungsten-phosphorus is preferably 5% or less for tungsten, 9% or more for phosphorus, and more preferably, 9% or more for phosphorus. 0.5%
Not less than 2% and not less than 10% and not more than 13.5% of phosphorus. By setting such a specific composition range, the corrosion resistance of the fluorinated passive film formed thereon is remarkably improved. The point is to gain.

At this time, if the composition range of the nickel alloy thin film deviates from the specific range, the corrosion resistance of the fluorinated passivation film is not significantly improved.

In the present invention, the composition range of each of the nickel alloy thin films is set to the above-mentioned specific range in comparison with the invention of Japanese Patent Application No. 2-283151 previously filed by the present inventors. Except for the above, the technology of the above-mentioned prior invention is adopted as it is.

[0014]

As described above, a large number of special gases having high reactivity and corrosiveness are used in a semiconductor process, and a process in the most severe atmosphere such as an ion bombardment apparatus is required.
In addition, it is an essential condition for improving the yield that these processes are always performed under constant conditions.

[0015] However, the conventional apparatus does not have sufficient corrosion resistance, and corrosion due to the process is a serious problem. Further, constant process conditions cannot always be obtained due to the deposition of by-products and the like generated by the process on the apparatus. Therefore, by periodically opening and cleaning the device,
A method for keeping process conditions constant is common.

By employing the industrial material of the present invention in the above-described process, not only corrosion of the apparatus can be prevented, but also removal of deposits generated by the process can be solved without opening the apparatus. In other words, the improvement of corrosion resistance and ion bombardment resistance makes it possible to use active gas, plasma, and the like, and therefore, it becomes possible to perform hermetic cleaning in which deposits generated by the process are converted into volatile gases and removed. . The opening of the process equipment not only extremely lowers the operation rate, but also is the most important problem to be overcome in the production of the ultra-highly integrated semiconductor required in the future. The present invention can solve the above problems.

[0017]

The present invention will be described below with reference to examples.

[0018]

Embodiment 1 In this embodiment, a base material of a test material having a fluorinated passivation film formed on a surface thereof is an aluminum alloy (#
5086) was used. Electroless plating of nickel / tungsten / phosphorus having different contents was applied to the surface of the test material, respectively, and the respective plating surfaces were subjected to a fluorinating passivation treatment.

The conditions of the fluoridation treatment are the same for all the test materials. After fluorination at 350 ° C. for 80 minutes, heat treatment is performed at 350 ° C. for 12 hours in an inert gas.

The test materials are A, B, C, D, E, F, G,
H, I consist of nine types, test materials D, E, F, G, H,
I is a substantially single phase nickel tungsten alloy according to the present invention.
It has a fluorinated passivation film formed on a phosphorus alloy thin film.

Test materials A, B, C, D, E, F, G, H,
Among A, A, B and C exemplified as comparative examples have a fluorinated passivation film formed on a mixed phase nickel-tungsten-phosphorus alloy thin film composed of nickel and a nickel alloy.

Table 1 shows the test materials A, B, C, D, E, F,
For each of the nickel-tungsten-phosphorous plating films of G, H, and I, the pH of the plating solution, the film thickness, the weight percent of nickel-tungsten-phosphorus in the plating film, and the magnetism of the plating film and 350 ° C. × 1 hour, This shows the magnetism after heat treatment at 350 ° C. for 8 hours. The analysis of each weight% is based on EPMA (Ele
ctron Probe Micro Analysis
s).

[0023]

[Table 1]

[0024]

Embodiment 2 FIG. 1 shows a relationship curve between the pH of a plating solution and the contents of tungsten and phosphorus concentrations in a plating film when performing nickel-tungsten-phosphorus plating. The plating of each test material is performed in a plating solution composed of nickel sulfate, sodium hypophosphite, sodium tungstate, and an organic acid, and the temperature during the plating is 82 to 90 ° C. It is clear from FIG. 1 that the concentrations of tungsten and phosphorus in the plating film greatly depend on the pH of the plating solution.

[0025]

Example 3 Relationship between pH of Plating Solution and Nickel-Tungsten-Phosphorus Plating Solution and Magnetism of Plating Film, and Magnetic Curve of Plating Film Heat-treated in Air at 350 ° C. for 1 and 8 Hours Is shown in FIG.

[0026]

Example 4 Samples A, B, C, D, E, F, G, H,
X-ray diffraction diagrams of the fluorinated passivation film formed on I are shown in FIG.
To 11 sequentially. Samples A, B and C have Ni and Ni
_A diffraction peak consisting of a mixed phase of ₃ P is observed. In particular, a large diffraction peak of Ni is observed in the test sample C.

On the other hand, test materials D, E, F,
No diffraction peak of Ni or Ni ₃ P is observed in G, H, and I, and it is confirmed that the plating film is composed of single-phase nickel-tungsten-phosphorus.

[0028]

Embodiment 5 XPS (X-ra) of a fluoride film formed on the surface of a nickel-tungsten-phosphorus-plated alloy thin film
y photoelectron spectrum
try) The analysis results are shown in FIG. It is recognized that the formed fluoride film is a film of nickel fluoride containing neither tungsten nor phosphorus. In FIG. 12, the sputtering time corresponds to the depth from the surface.

[0029]

Embodiment 6 FIG. 13 shows the plasma resistance of a fluoride film formed on a nickel-tungsten-phosphorus-plated alloy thin film.
Shown in FIG. 13 shows the ratio of the remaining fluoride film after irradiating the fluoride film with CF ₄ plasma having different intensities for 30 minutes. It is recognized that the fluoride film according to the present invention exhibits excellent plasma resistance even with a plasma of 60 eV.

[0030]

Embodiment 7 Table 2 shows the results of evaluating the adhesion of the nickel-tungsten-phosphorus plating film and the fluoride film formed on the surface of the plating film. The measurement was performed by immersing the sample in liquid nitrogen for 1 minute, then immersing it in boiling water for 1 minute to make one cycle, and repeatedly performing 10 cycles under the same conditions.
As shown in Table 2, no peeling was observed at all under the severe conditions, and excellent adhesion was exhibited.

[0031]

[Table 2]

[0032]

Embodiment 8 FIG. 14 shows a measuring apparatus used for polarization measurement of a fluoride film formed on a nickel-tungsten-phosphorus-plated alloy thin film.

The measurement was performed with a sample area of 1 cm ² and an electrolyte of 1 N-A.
The measurement was performed by a potential scanning method using 1 Cl ₃ (40 ° C.) and an electric sweep rate of 30 mV / min. All the measurements were performed in a nitrogen atmosphere, and the dissolved oxygen in the electrolytic solution, which is a major error factor in the measurement, was sufficiently deaerated with high-purity nitrogen before the measurement. The measurement of the current value is also improved so that it can be measured at an extremely low order of nA / cm ² , and the excellent passivation film characteristics of the fluoride film can be evaluated.

[0034]

Embodiment 9 FIGS. 15 to 17 show test materials A, B, C, D,
1N of fluorinated passivation film formed on E, F, G, H, I
9 shows the results of polarization measurement in an AlCl ₃ solution at 25 ° C.

Specimens A, B, C, D, E, F, G, H,
Of I, test materials D, E, F, G, H, I according to the present invention
Shows that no current is observed even in a microcurrent region of nA / cm ² up to a high potential as compared with other test materials, and it is recognized that the film is a good passive film. In particular, it is recognized that the fluorinated passivation formed on the test materials D and E exhibits extremely excellent passivation characteristics.

[0036]

[Brief description of the drawings]

[0037]

FIG. 1 is a graph showing the relationship between the pH of a plating solution and the contents of tungsten and phosphorus in a plating film.

[0038]

FIG. 2 shows a relationship between pH in a plating solution and magnetism of a plating film and a magnetic curve at the time of heating.

[0039]

FIG. 3: Material on which a fluorinated passivation film is formed (test material A)
FIG.

[0040]

FIG. 4: Material on which a fluorinated passivation film is formed (test material B)
FIG.

[0041]

FIG. 5: Material on which a fluorinated passivation film is formed (test material C)
FIG.

[0042]

FIG. 6: Material on which a fluorinated passivation film is formed (test material D)
FIG.

[0043]

FIG. 7: Material on which a fluorinated passivation film is formed (test material E)
FIG.

[0044]

FIG. 8: Material on which a fluorinated passivation film is formed (test material F)
FIG.

[0045]

FIG. 9: Material on which a fluorinated passivation film is formed (test material G)
FIG.

[0046]

FIG. 10 is an X-ray diffraction diagram of a material having a fluorinated passivation film (test material H).

[0047]

FIG. 11 is an X-ray diffraction diagram of a material having a fluorinated passivation film (test material I).

[0048]

FIG. 12 is an xps diagram of a fluorinated passivation film.

[0049]

FIG. 13 is a view showing plasma resistance characteristics of a fluorinated passivation film.

[0050]

FIG. 14: An apparatus for measuring polarization of a fluorinated passivation film.

[0051]

FIG. 15 is a graph showing the results of polarization measurement of the above materials.

[0052]

FIG. 16 is a graph showing the results of polarization measurement of the above materials.

[0053]

FIG. 17 is a graph showing polarization measurement results of the above materials.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Magoro Maeno 2-42-6 Komyodai, Izumi-shi, Osaka (72) Inventor Ryoji Hirayama 3-482, Mozujintoryominamicho, Sakai-shi, Osaka (72) Inventor Hiroshi Izumi Person 1-19-30 Kamo, Takaishi-shi, Osaka (72) Inventor Kazuo Chiba 3-22-3, Fuyodai, Mishima-shi, Shizuoka (72) Inventor Kazuka Mikasa 1086-166, Oba, Mishima-shi, Shizuoka (72) Inventor Takahashi Reiko 521-1 Oka Isshiki, Numazu City, Shizuoka Prefecture (58) Field surveyed (Int. Cl. ⁷ , DB name) C23C 28/00 C23C 18/36 C23C 22/34 C23F 15/00 H01L 21/314

Claims (4)

(57) [Claims] 1. A composition comprising nickel, tungsten, and phosphorus on a surface of a base material, the composition range of which is 5% of tungsten.
An industrial material comprising: forming an alloy thin film of the following and 9% or more of phosphorus; and forming a fluorinated passivation film containing no tungsten and phosphorus on at least the surface of the alloy thin film. 2. A composition comprising nickel, tungsten, and phosphorus on the surface of a base material, the composition range of which is set to 0.1 wt.
An alloy thin film of 5% or more and 2% or less and phosphorus of 10% or more and 13.5% or less is formed, and a fluorinated passivation film containing no tungsten and phosphorus is formed on at least the surface of the alloy thin film. The industrial material according to claim 1. 3. The industrial material according to claim 1, wherein said base material is formed of a metal or an alloy thereof. 4. The industrial material according to claim 1, wherein said base material is formed of ceramics or plastic.