JPS63286575A - Production of rigid carbon film - Google Patents

Abstract

PURPOSE:To form a rigid carbon excellent in adhesion on a substrate by forming an islandlike crystalline intermediate layer on the substrate and bringing this substrate into contact with the gas which is obtained by exciting a gaseous raw material contg. a gaseous carbon source. CONSTITUTION:A crystalline intermediate layer (Si, Ti, W or the like) is formed in an islandlike state on the surface of a substrate (Si, Al, Fe or the like) by means of resistance heating vapor deposition. At this time, reaction pressure is regulated to about 10<-10>-10<-3>Torr and reaction time is regulated to about 5min or below. Thereafter the gas obtained by exciting a gaseous raw material contg. a gaseous carbon source (methane, acetone, methyl alcohol or the like) is brought into contact with this substrate at the prescribed temp. at about 10<-9>-10<3>Torr reaction pressure. Thereby a diamond-like carbon film or the like excellent in adhesion is formed on the substrate.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for producing a hard carbon film, and more specifically, a hard carbon film that has excellent adhesion and is suitable for various protective films, such as a diamond film or The present invention relates to a method for manufacturing a hard carbon film that can form a diamond-like carbon film.

[Prior art and its problems] In recent years, hard carbon film manufacturing technology has been making remarkable progress.

So far, we have developed methods such as plasma CVD (CVD) to obtain a hard carbon film on the substrate surface by plasma decomposition of hydrocarbons, chemical transport (CVD) method to obtain a hard carbon film on the substrate surface by utilizing a disproportionation reaction, Various manufacturing techniques have become known, such as ionized vapor deposition using a hot cathode PIG gun, a cold cathode PIG gun, or a sputter gun.

However, in all of these conventional methods, a hard carbon film is formed directly on a substrate made of, for example, metal or ceramics, so there is a problem that the resulting hard carbon film easily peels off from the substrate. Yes, for example, a hard carbon film can be used to protect the surface of a tool! When used as a membrane,
There was a problem that the protective film was easily peeled off and its life as a protective film was short.

[Objective of the Invention] The object of the present invention is to solve the above-mentioned problems, and to solve the above-mentioned problems by using any method such as high frequency plasma CVD method, microwave plasma CVD method, hot filament CVD method, chemical transport method, ionization vapor deposition method, ion beam vapor deposition method, etc. It is an object of the present invention to provide a method for producing a hard carbon film, which allows a hard carbon film with excellent adhesion, such as a diamond film or a diamond-like carbon film, to be obtained even when

[Means for achieving the above object] In order to achieve the above object, the inventor has made extensive studies and found that if a hard carbon film is formed after providing a specific intermediate layer on a substrate, the adhesion will be poor. This invention was achieved by discovering that an excellent hard carbon film can be obtained.

That is, the outline of the present invention is to form an island-shaped crystalline intermediate layer on a substrate, and then apply a gas obtained by exciting a raw material gas containing a carbon source gas to the island-shaped crystalline intermediate layer. This is a method for producing a hard carbon film, which is characterized by bringing the film into contact with a formed substrate.

The substrate is not particularly limited, and includes, for example, metals such as silicon, aluminum, iron, nickel, titanium, tungsten, molybdenum, cobalt, and chromium, alloys thereof, oxides, nitrides, and carbides of the metals, and Al2.
Any of cermets such as 03-Fe type, Tie-Xi type, T1C-Ca type, and FhC-Fe type, and various ceramics can be used.

In the method of the present invention, a crystalline intermediate layer is formed in an island shape on the substrate. Forming this crystalline intermediate layer in an island shape improves the adhesion between the substrate and the hard carbon film.

Examples of raw materials for the crystalline intermediate layer include silicon,
Examples include titanium, tungsten, aluminum, chromium, tantalum, and zirconium.

A conventionally known method can be used to form the crystalline intermediate layer. As a specific example, the raw material for the crystalline intermediate layer is usually IX
A vacuum evaporation method in which the crystalline intermediate layer is deposited on the substrate by heating and evaporating it in a high vacuum with a pressure lower than 1O-6 tarr: Ionize the raw material,
An ion blating method such as a DC excited ion blating method, a radio frequency excited ion blating method, a cluster ion beam method, or an ion beam evaporation method in which the crystalline intermediate layer is deposited on the substrate by accelerating it with an electric field; A beam spatter method in which a raw material is pumped out into a vacuum and deposited on the substrate, a two-pole DC sputter method,
Sputtering methods such as bipolar AC sputtering, three-pole DC sputtering, and magnetron sputtering; activating particles of the raw material for the crystalline intermediate layer in a plasma state, and depositing the activated particles on the substrate. Examples include plasma CVD method.

In the method of the present invention, when forming the crystalline intermediate layer, together with the raw material for the crystalline intermediate layer, for example,
Gases such as oxygen, nitrogen, ammonia, methane, acetylene, and ethylene can also be used.

In the method of the present invention, the reaction proceeds under the following conditions, and a crystalline intermediate layer is formed in the form of an island on the substrate.

That is, the temperature of the surface of the substrate differs depending on the means for forming the crystalline intermediate layer and the raw material.

The reaction pressure is usually 1010 to IQ-3 tarr.

If the reaction pressure is lower than 10 i' torr, the rate of formation of the crystalline intermediate layer will be slow or the crystalline intermediate layer will not be formed. On the other hand, ICl−”torr
Even if it is made higher, the corresponding effect cannot be obtained.

The reaction time varies depending on the raw materials, but is usually 5 minutes or less. If the heating time exceeds 5 minutes, the crystalline intermediate layer may not be formed in the form of islands.

The crystalline intermediate layer is usually formed in one step under the above conditions, but for example, ion beam evaporation, plasma CVD, etc.
When an amorphous intermediate layer is formed on a substrate by a forming method such as the D method, the amorphous intermediate layer is made crystalline by performing 72-ring. If this intermediate layer is not crystalline, the resulting hard carbon film will have poor adhesion.

In the method of the present invention, after forming the crystalline intermediate layer in an island shape on a substrate, a gas obtained by exciting a raw material gas containing at least a carbon source gas is used to form the island-shaped crystalline intermediate layer. A hard carbon film, such as a diamond film or a diamond-like carbon film, is formed on the substrate.

Examples of means for exciting the source gas to obtain a gas containing excited carbon include conventionally known methods such as plasma CVD, sputtering, ionization deposition, ion beam deposition, thermal filament method, and chemical transport method. The following method can be used.

The raw material gas contains at least a carbon source gas, and may also contain an inert gas.

Examples of the carbon source gas include methane, ethane,
Alkanes such as propane, butane, pentane, hexane, alkenes such as ethylene, propylene, butene, pentene, butadiene, alkynes such as acetylene,
Examples include aromatic hydrocarbons such as benzene, toluene, xylene, indene, naphthalene, and phenanthrene, cycloparaffins such as cyclopropane and cyclohexane, and cycloolefins such as cyclopentene and cyclohexene.

In addition, carbon source gases include carbon oxide, carbon dioxide, oxygen-containing carbon compounds such as methyl alcohol, ethyl alcohol, and acetone, and nitrogen-containing compounds such as mono(di,tri)methylamine, mono(di,tri)ethylamine, and aniline. Carbon compounds and the like can also be used.

These can be used alone or in combination of two or more.

Among these, preferred are paraffinic hydrocarbons such as methane, ethane, and propane, ketones such as amethane and benzophenone, and alcohols such as pertyl alcohol.

The inert gas has the function of a carrier for the carbon source gas and, in particular, 1. When a sputtering method, an ionization vapor deposition method, or an ion beam vapor deposition method is employed, carbon atoms are ionized in an arc discharge space to knock out carbon atoms and ionize the carbon.

Specific examples of the inert gas include hydrogen gas, argon gas, neon gas, helium gas, xenon gas, and nitrogen gas.

Among these, hydrogen gas in particular is produced by forming plasma by high-frequency or microwave irradiation in the plasma CVD method, and is converted into atomic hydrogen by heat or electric discharge in CVD methods such as pyrolysis, chemical transport, and thermal filament methods. form.

This atomic hydrogen has the effect of removing graphite-structured carbon that precipitates simultaneously with the precipitation of diamond or diamond-like carbon.

The inert gas may be used alone or in combination of two or more.

In the method of this invention, the reaction proceeds under the following conditions, and diamond or diamond-like carbon is deposited on the substrate on which the crystalline intermediate layer is formed.

That is, since the temperature of the surface of the substrate on which the crystalline intermediate layer is formed differs depending on the source gas excitation means, -
Although it cannot be determined generally, for example, plasma CV
When method D is used, the temperature is usually room temperature to 1.000°C, preferably room temperature to 95 G''C. If this temperature is lower than room temperature, excited state carbon may not be produced. On the other hand, even if the temperature is higher than 1.000°C, no corresponding effect will be achieved.

The reaction pressure is usually 101 to 103 torr, preferably 101 to 103 torr.
When it is lower than -9 torr, the precipitation rate of diamond or diamond-like carbon becomes slow, or diamond or diamond-like carbon does not precipitate. On the other hand, even if it is made higher than 103 torr, a corresponding effect cannot be obtained.

The diamond or diamond-like carbon obtained by the method of this invention has excellent adhesion and does not have the problem of easy peeling, so it can be suitably used as a surface protective film for cutting tools, for example. can.

[Effects of the Invention] According to the present invention, no matter which method is used, such as a high frequency plasma CVD method, a microwave plasma CVD method, a hot filament CVD method, a chemical transport method, an ionization vapor deposition method, an ion beam vapor deposition method, etc. For example, diamond films or diamond-like carbon films with excellent adhesion can be formed on substrates made of metals, ceramics, cermets, etc. It is possible to provide an industrially advantageous method for producing a hard carbon film that can be suitably used for forming a protective film when used.

[Example] Next, Examples and Comparative Examples of the present invention will be shown to further specifically explain the present invention.

(Example 1) Using vacuum evaporation equipment W (manufactured by Shinku Kikou), the pressure was 10-'
A reaction was carried out for 5 minutes by a resistance heating vapor deposition method under the condition of torr to form silicone crystals in the form of islands on a substrate made of tungsten carbide (WC).

Next, this substrate was placed in a reaction chamber of a commercially available microwave plasma CVD apparatus, and methane gas was introduced into the reaction chamber at a flow rate of 0.
．． 5 ace layer and hydrogen gas were introduced at a flow rate of 100 scc layer, and the substrate temperature was 900° C. and the pressure was 5.5 scc.
Under the condition of 3 Kpa, the output of the 2.45 GHz microwave power source was set to 600 W, and the reaction was carried out for 4 hours to obtain a deposit with a thickness of 2 m on the substrate controlled at the above temperature.

When the obtained deposit was subjected to Raman spectroscopic analysis, it was confirmed that the Raman scattering spectrum showed a sharp peak near 1333 cm-1, and that it was diamond.

In addition, a tensile method was used in which adhesion was measured by attaching a ribbed/ When the adhesion of this diamond film was measured, it was found to be 1000 kg/cm2 or more.

(Comparative Example 1) A diamond film was manufactured in the same manner as in Example 1 except that silicon crystals were not formed.

When the adhesion of the obtained diamond-like carbon film was evaluated, it was found that the diamond-like carbon film weighed 200 kg.
It was easily peeled off from the substrate with a force of /am2.

(Example 2) Using a vacuum evaporation device (manufactured by Shinku Kikou 111), the pressure was 1O.
A reaction was carried out for 5 minutes under the condition of −2 torr by a resistance heating method to form island-shaped tungsten crystals on a substrate made of tungsten carbide (WC).

Next, this substrate was placed in a reaction chamber of a commercially available hot filament device, and acetone gas was introduced into the reaction chamber at a flow rate of 0.8 s.
Hydrogen gas was introduced into the CC layer at a flow rate of 100 gccm, and these gases were thermally decomposed under conditions of a substrate temperature of 800°C and a pressure of 8.7 Kpa, but no clouding reaction occurred.
A film with a thickness of 8 pm was deposited on the substrate controlled at the above temperature.
deposits were obtained.

When the obtained deposit was subjected to Raman spectroscopic analysis, a sharp peak near 1333 cm-1 was observed in the Raman scattering spectrum, and it was confirmed that the deposit was diamond.

Furthermore, when the adhesion of this diamond was evaluated in the same manner as in Example 1, it was found that the adhesion was 1000 kg/am2.
That was it.

Patent Applicant Idemitsu Petrochemical Co., Ltd. Agent Patent Attorney Fukuso Okidana・7r・-′Par-1
So, , name 4. ．． −・

Claims (2)

[Claims] (1) An island-shaped crystalline intermediate layer is formed on the substrate, and then a gas obtained by exciting a raw material gas containing a carbon source gas is brought into contact with the substrate on which the island-shaped crystalline intermediate layer is formed. A method for producing a hard carbon film, characterized in that: (2) Claim 1, wherein the crystalline intermediate layer contains silicon atoms and/or tungsten atoms.
The method for producing a hard carbon film as described in .