JPH01147068A - Method and apparatus for manufacturing hard carbon film - Google Patents

Abstract

PURPOSE:To form a high-hardness hard carbon film at high speed by disposing a third electrode between an anode and a cathode and bringing a plasma of carbon source gas excited by glow discharge and hollow cathode discharge into contact with a substrate. CONSTITUTION:In a reaction chamber 4 in a high-frequency plasma CVD apparatus 1, a third electrode 7 having an electric potential identical with that of a cathode 6 is disposed between an anode 5 and the cathode 6. A substrate 8 is disposed between the cathode 6 and the third electrode 7, and the cathode 6 is connected to a high-frequency electric power source 9. A carbon source gas and a carrier gas are introduced via an introducing hole 2, and high-frequency waves are impressed on the electrodes. Then, glow discharge is produced between the anode 5 and the third electrode 7 and hollow cathode discharge is produced between the third electrode 7 and the cathode 6, by which a carbon gas source is excited and plasma is produced. By bringing this plasma into contact with the substrate 8, the hard carbon film can be formed on the substrate 8.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing a hard carbon film and an apparatus for manufacturing the same. The present invention relates to a method for producing a hard carbon film that can form a film at high speed, and an apparatus for manufacturing the same.

[Prior art and its problems] Conventionally, a high-frequency plasma device is used to generate plasma by glow-discharging a carbon source gas in a reaction chamber, and the plasma is brought into contact with a substrate to form diamond-like carbon and/or carbon on the substrate. Alternatively, techniques for forming diamond films are known.

This technique is commonly used in semiconductor processes such as film formation and etching during LSI manufacturing.

Furthermore, a technique is also known in which a carbon source gas is subjected to hollow cathode discharge in a reaction chamber using a similar device to form a film of diamond-like carbon and/or diamond on a substrate.

Compared to glow discharge, hollow cathode discharge has the advantages of high plasma density and relatively wide energy range, but has the disadvantage of having a small stable mode region.

Both of the above-mentioned techniques are excellent techniques used to obtain hard carbon films, but there is a long-awaited ability to obtain even higher hardness films at higher speeds.

An object of the present invention is to provide a method for manufacturing a hard carbon film and an apparatus for manufacturing the same, which are further improved over the above-mentioned prior art and can produce a hard carbon film with high hardness at a higher speed.

[Means for Solving the Problems] As a result of intensive research by the present inventors to achieve the above object, the present inventors have developed a high-frequency plasma CVD apparatus.

A third electrode is disposed between the anode and the cathode placed in the reaction chamber, and a carbon source gas plasma excited by glow discharge and hollow cathode discharge is brought into contact with the substrate to form a hard carbon film with high hardness. They discovered that it can be formed at high speed and succeeded in developing a manufacturing method and a manufacturing apparatus, thereby completing the present invention.

That is, in the first configuration of the present invention, an anode and a cathode are arranged to face each other in a reaction chamber, and a third electrode having the same potential as the cathode is arranged between the anode and the cathode. 11) introducing a carbon source gas into the substrate, and exciting the carbon source gas by discharging between the anode and the third electrode and between the anode and the third electrode, respectively. A method for producing a hard carbon film, the method comprising:
A second configuration of the present invention is that in a high-frequency plasma CVD apparatus, an anode and a cathode are placed opposite each other in a reaction chamber having an introduction hole for introducing a carbon source gas, and the potential is the same as that of the cathode. This is a hard carbon film manufacturing apparatus characterized by disposing a third electrode.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A manufacturing method according to an embodiment of the present invention will be described below with reference to the drawings.

In the high-frequency plasma CVD apparatus shown in FIG. (The RF main electrode is arranged to face each other, and a third electrode 7 having the same potential as the cathode 6 is arranged between them.

A substrate 8 having a hard carbon film formed on its surface is arranged between the cathode 6 and the third electrode 7, and the cathode 6 is connected to a high frequency power source 9.

Here, when a carbon source gas and a carrier gas are introduced through the introduction hole 2 and a high frequency is applied to the electrode by a high frequency power source 9, a glow discharge is generated between the anode 5 and the third electrode 7.
A hollow cathode discharge occurs between the third electrode 7 and the cathode 6 to excite the carbon source gas and generate plasma.The plasma contacts the substrate 8 and forms a hard carbon film on the substrate 8.

The 7Ji plate 8 can be heated by embedding a heater in the cathode 6 or by heating with a lamp.

In the method of the present invention, glow discharge is performed using the anode 5 and the third electrode 7, so the anode 5 is not particularly limited as long as it has the shape and size necessary for performing the glow discharge, for example. A flat anode can be mentioned.

The third electrode 7 introduces the plasma generated by the glow discharge between the third electrode 7 and the cathode 6, and also performs a hollow cathode discharge between the third electrode 7 and the cathode 6.
The electrode 7 may be shaped like a wire mesh, a grid, or a shelf, and the third electrode 7 and the cathode 6 may be plate-shaped electrodes arranged opposite to each other.

:53 As long as the electrode 7 and the cathode 6 perform hollow cathode discharge as described above, various embodiments other than those described above can be adopted. The wire mesh is used as an anode 5.
Examples include a cathode that is disposed opposite to the bottom and has the bottom inner surface of the bottomed cylindrical body as the substrate mounting surface. Further, the cathode may have various shapes such as a flask shape, a truncated cone shape, and a truncated pyramid shape having an opening (note that the third electrode is arranged in the opening).

When the third electrode 7 is shaped like a wire mesh, it is preferable that the third electrode 7 has a mesh size of 1 to 500 meshes.

The distance between the anode 5 and the cathode 6 is usually 20 to 300
mm, and the distance between the h-pole 6 and the third electrode 7 is usually 1
It is 0-200m+s.

In the method of the present invention, the material of the substrate 8 on which the hard carbon film, that is, the diamond-like carbon and/or diamond film is formed, is not particularly limited, and for example, glass, synthetic resin, metal, ceramics, etc. are used. Among them, glass and synthetic resin are preferred.

The above-mentioned glass is not particularly limited, and examples include quartz glass, 9H quartz glass, soda lime glass (window glass), solar lime glass (plate glass), soda lime glass (pin glass), and soda lime glass (light bulb glass).
, practical glasses such as lead glass, aluminoborosilicate glass, low expansion borosilicate glass, low loss borosilicate glass, tungsten-sealed borosilicate glass and aluminosilicate glass for electrical, optical and craft applications can be mentioned. .

Further, the glass that can be used in the present invention can also include optical glass, chemically strengthened glass, photochromic glass, crystallized glass, and the like.

The plastics are not particularly limited, and ordinary ones can be used, such as polyolefin resins, fluororesins, vinyl chloride resins and copolymer resins thereof, vinylidene chloride resins, polystyrene and copolymer resins thereof, etc. general-purpose resins, polyamide resins, and polyacetals.

Examples include engineering plastics such as polycarbonate, thermoplastic polyester resin, polyphenylenoxide, noryl resin, and polysulfone.

Examples of the polyolefin resin include ultra-high density polyethylene, high-density polyethylene, medium- and low-density polyethylene, linear low-density polyethylene, isotactic polypropylene, syndiotactic polypropylene,
Examples include polypropylene of atactic polypropylene, polybutene, 4-methylpentene-1 resin, etc. In the present invention, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ethylene-vinyl chloride copolymer Copolymers with olefins such as propylene-vinyl chloride copolymers can also be used.

Examples of the fluororesin include Teflon.

Examples of the vinyl chloride copolymer resin include vinyl chloride-vinyl acetate resin, vinyl chloride-vinylidene chloride copolymer resin, and vinyl chloride-acrylonitrile copolymer resin.

Examples of the vinyl acetate resin include vinyl acetate resin, polyvinyl acetoacetal, polyvinyl butyral, and the like.

As the polystyrene copolymer resin, for example, A
Examples include BS resin, SAN resin, AC3 resin, and the like.

Examples of the polyamide resin include nylon 6,
Nylon 8, Nylon 11, Nylon 8B, Nylon 6
One example is 1O'v.

The polyacetal may be a single polymer or a copolymer.

Examples of the polycarbonate include polycarbonate obtained from bisphenol A and phosgene, polycarbonate obtained from bisphenol A and diphenyl carbonate, and the like.

Examples of the thermoplastic polyester resin include polyethylene terephthalate, polypropylene terephthalate, and the like.

Which material to use can be appropriately determined depending on the intended use of this hard carbon film-coated substrate.

The hard carbon film formed on the substrate mentioned above may be, for example, a diamond-like carbon film, a diamond film, or a mixed film of diamond-like carbon and diamond.

For example, 100 is 50% of the hard carbon film on the substrate.
It is formed with a thickness of 0 to 10,0 OOA.

In the present invention, carbon source gases include, for example, alkanes such as methane, ethane, propane, butane, pentane, and hexane, alkenes such as ethylene, propylene, butene, pentene, and butadiene, alkynes such as acetylene, benzene, Examples include aromatic hydrocarbons such as toluene, xylene, indene, naphthalene, and phenanthrene, cycloparaffins such as cyclopropane and cyclohexane, and cycloolefins such as cyclopentene and cyclohexene.

Further, as the carbon source gas, carbon oxide, carbon dioxide, oxygen-containing carbon compounds such as methyl alcohol and ethyl alcohol, and nitrogen-containing carbon compounds such as methylamine, ethylamine and aniline can also be used. moreover,
Although it is not a single item, it is classified as Class 4 hazardous materials under the Fire Service Act, such as gasoline.
Type 1 petroleums, kerosene, turpentine oil, camphor oil, pine oil, etc., tertiary petroleums, heavy oils, etc., and tertiary petroleum oils, such as gear oils, cylinder oils, etc., can also be effectively used. Moreover, the various carbon compounds mentioned above can also be used in combination.

Among the above carbon source gases, methane, carbon oxide, carbon dioxide, etc. are preferred.

The carrier gas is important not only as a carrier for introducing the carbon source gas into the plasma reaction system, but also in stably generating and sustaining plasma.

Examples of such carrier gas include hydrogen gas, argon gas, neon gas, helium gas, xenon gas, and nitrogen gas.

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

Among the gear gases mentioned above, hydrogen gas, nitrogen gas, argon gas, etc. are preferred.

In the present invention, the carbon source gas or a mixed gas of the carbon source gas and carrier gas is supplied from the introduction hole 2 into the reaction chamber 4 in which the substrate 8 is disposed, and is heated to the cathode 6 while heating the substrate 8. A high frequency is applied to generate a glow discharge between the anode and the third electrode, and a hollow cathode discharge is generated between the cathode 6 and the third electrode 7 to excite the carbon source gas or mixed gas and generate a plasma. A hard IA carbon film, that is, a diamond-like carbon film and/or a diamond film is formed on the substrate 8 by generating .

In the method of the present invention, the carbon source gas is e.g.
A flow rate of 500 cc/min is supplied, and a carrier gas is supplied at a flow rate of 1 to 1,000 cc/min.

The reaction pressure in the method of the present invention, that is, the pressure inside the reaction chamber, is usually 10-5 to 103 Torr, preferably 10-3 to 102 Torr. If this reaction pressure is lower than 10-5 Tart, the rate of formation of the hard carbon film may be significantly slowed down. On the other hand, 103To
If it is higher than rr, a hard carbon film may not be formed.

In addition, the heating temperature of the substrate is usually room temperature to 1.000°C,
Preferably, the temperature is room temperature to 900°C. If this temperature is lower than room temperature, excited state carbon may not be produced. On the other hand, even if heated to a temperature of 1,000° C. or higher, the corresponding effect cannot be obtained. Furthermore, when plastic is selected as the material, it is preferable to set the temperature to a temperature at which the heat resistance of the plastic is lower.

A substrate on which a hard carbon film is formed by the method of the present invention can be used, for example, as a wear-resistant tool, a wear-resistant optical element, a magnetic disk, a speaker diaphragm, a heat sink, etc. Also, a container-shaped substrate can be used, for example.

Beakers, flasks, various glass dishes such as crystallizers and evaporating dishes, bottles such as weighing bottles, suction bottles, sampling bottles, condensers, desiccators, suction bags, pipettes, graduated cylinders, billets, funnels, kip gas generators It can be widely used in laboratory equipment such as filters, household items such as cups, plates and bowls, and industrial parts such as steel pipes lined with glass formed with a diamond-like carbon film or diamond film on the surface. .

[Example] Hereinafter, the present invention will be explained in more detail by way of examples.

(Example 1) The anode, the 113 electrode, and the third electrode (1B mesh) were placed in a reaction chamber in which the distance between the anode and the cathode was 90 mm, and the distance between the third electrode and the cathode was 30 mm. A glass substrate (length: 50 m, radius: 50 mm, thickness: 2 cm) was placed on the cathode.

Next, the pressure inside the reaction chamber was reduced to 10-2 Torr, and the substrate was heated to 100°C. Methane gas was introduced as a carbon source gas through the introduction hole at a rate of 50 seconds.

After that, when a high frequency of 13.58 MHz was applied with an output of 300 watts, a glow discharge was generated between the anode and the third electrode, and plasma was generated between the third electrode and the cathode due to a hollow cathode discharge, and the substrate A diamond-like carbon film with a thickness of 2 pLm was formed on top.

The obtained substrate showed the following results.

1) Y & membrane speed: 210A/win2) Knoop hardness: 5,100kg/intestine■? 3) Raman scattering spectroscopy: A wide peak from 1100 to 1700 cm was detected. (Peak specific to i-carbon) (Comparative Example 1) The same operation as in Example 1 was performed except that the third electrode was not used, and a glow discharge was generated between the electrodes to create a thickness on the surface. A substrate on which a 2 gm diamond-like carbon film was formed was obtained.

Regarding the obtained substrate, the following results were obtained.

l) Film formation rate: 80 A/+5in2) Knoop hardness: 4,000 kg/llm23) Raman scattering spectroscopy: Same as Example 1.

(Comparative Example 2) Example 1 except that the anode was not used in Example 1.
In the same manner as above, hollow cathode discharge was generated between the electrodes to obtain a substrate on which a diamond-like carbon film with a thickness of 2 gm was formed.

The following results were obtained for the obtained substrate.

l) Film forming rate: 140A/win2) Knoop hardness: 4,700 kg/mm23) Raman scattering spectroscopy: Same as Example 1.

[Effect of the invention] As explained above, according to the method of the present invention.

In a conventional high-frequency plasma device, the film formation rate is faster at the same power consumption than when glow discharge or hollow cathode discharge is used alone, and the hard carbon film obtained is also hard. In addition, the device of the present invention has a simple configuration in which a third electrode having the same potential as the cathode is placed between the anode and the cathode, and generates plasma by both glow discharge and hollow cathode discharge, resulting in high film formation speed and high hardness. carbon membranes can be manufactured.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing a high frequency plasma apparatus which is an embodiment of the present invention. ■...High frequency plasma device device 4...Reaction chamber 5φ...Anode 6...Cathode 7...Third electrode Patent applicant Idemitsu Petrochemical Co., Ltd. Agent Patent attorney Naoki Fukumura Figure 1

Claims (2)

[Claims] (1) disposing an anode and a cathode facing each other in a reaction chamber, disposing a third electrode having the same potential as the cathode between the anode and the cathode, and introducing a carbon source gas into the reaction chamber; A hard carbon film characterized in that plasma obtained by exciting the carbon source gas by discharging between the anode and the third electrode and between the cathode and the third electrode is brought into contact with the substrate. manufacturing method. (2) In a high-frequency plasma CVD apparatus, a third electrode having the same potential as the cathode is arranged between an anode and a cathode that are arranged opposite each other in a reaction chamber having an introduction hole through which a carbon source gas can be introduced. A hard carbon film manufacturing device characterized by: