JPS62108798A - Production of diamond film or diamond like carbon film - Google Patents

Abstract

PURPOSE:To remarkably increase the density of the formed film by grinding the surface of a substrate with polishing powder having comparatively small mean particle diameter as pretreatment when a diamond film or a diamond like carbon film is formed on the substrate. CONSTITUTION:When the diamond film or the diamond like carbon film is formed on the substrate, the surface of the substrate is ground with polishing powder having <1mum mean particle diameter and then the diamond film or the diamond like carbon film is formed on the substrate. The mean particle diameter of the polishing powder is most preferably controlled to <=0.8mum. The diamond film or the diamond like carbon film can be formed on the substrate by vacuum deposition, chemical vapor growth, plasma chemical vapor growth, or an ion-beam method.

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention relates to a method for forming a diamond film or a diamond-like carbon film on the surface of each 81I substrate. Alternatively, the present invention relates to a diamond film or a method for manufacturing a diamond-like carbon film that can form a diamond-like carbon film.

[Technical background of the invention and its problems]

Diamond has the highest hardness and thermal conductivity of any currently known substance, and also has the highest elastic modulus, compressive strength, and g! It is a transparent and chemically stable substance with loquat properties. Therefore, in order to take advantage of its excellent properties, research is being carried out to develop applications such as wear-resistant coating for jigs and tools, protection for solar cells, optical lenses, and heat sinks for semiconductors. However, natural diamonds are produced in small quantities and are extremely expensive, so there is no way they can be used as industrial materials.

For this reason, research on the production of synthetic diamonds is actively being carried out, but synthetic diamonds produced using conventional methods under high temperature and high pressure are also expensive and have little utility as industrial materials. . 'Moreover, both natural diamonds and artificial diamonds are generally lumpy or granular in shape, making it difficult to produce a film, so the useful properties of diamond cannot be utilized optically.

For this reason, research has recently been actively conducted to produce diamonds even at low temperatures and low pressures, and moreover, to produce diamond films.

There are four main methods: That is, Raku 1 is a vacuum evaporation method in which a diamond-like carbon film is formed by irradiating diamond powder with a laser beam or an electron beam in a vacuum to heat and evaporate it, and then depositing the vapor on the substrate surface. In this method, a hydrocarbon such as methane, ethylene, or acetylene is introduced onto the surface of a heated substrate, and the hydrocarbon is thermally decomposed using the thermal energy of a hot filament placed close to the substrate to generate active 1, which causes the surface of the substrate to The third method is chemical vapor deposition to deposit diamond.

A plasma chemical vapor deposition method in which hydrocarbons are decomposed in plasma to generate active species, thereby depositing diamonds on the surface of a substrate.Fourthly, carbon-containing positive ions are generated from hydrocarbons or graphite, There is an ion beam method in which these positive ions are focused and bombarded onto the surface of a substrate to deposit diamond or diamond-like carbon on the surface of the substrate.

All of these methods are industrially advantageous because they are carried out at low temperatures and low pressures; however, the diamond film or diamond-like carbon film formed on the surface of the substrate by these methods is of high quality. However, it has drawbacks such as being easily black and opaque, and having a low density and many pores. Considering the excellent thermal conductivity of diamond, when diamond films or diamond-like carbon films are used as heat dissipators for electronic devices that generate a lot of heat, if the density of these patterns is low, the heat dissipation effect will be poor. Focusing on diamond's excellent electrical insulation,
When using various materials as a base and coating the surface with a diamond film or diamond-like carbon film to provide electrical insulation, if the density of these films is low, the withstand voltage may become extremely low, which is a fatal weakness. Therefore, for these purposes, there is a strong demand for a method for producing a high-density diamond film or diamond-like carbon XUIk.

[Purpose of the invention]

The present invention was made in response to the above request, and
It is an object of the present invention to provide a method for manufacturing a diamond film or a diamond-like carbon film that can form a diamond film or a diamond-like carbon film with a high density on each substrate using a very simple method.

[Summary of the invention]

As a result of intensive research to achieve the above object, the present inventors found that in the four diamond film manufacturing methods described above, it is possible to polish the surface of the substrate with an abrasive powder having a relatively small average particle size as a pretreatment. , the density of the diamond film or diamond-like carbon film that is formed increases dramatically! J! This discovery led to the development of the method of the present invention.

That is, the method for manufacturing a diamond film or diamond-like carbon film of the present invention is a manufacturing method for forming a diamond film or diamond-like carbon UK on a substrate, in which the surface of the substrate is polished with abrasive powder having an average particle size of less than 1 μm. The method is characterized in that a diamond film or a diamond-like carbon film is formed on the substrate.

First of all, terminology used in the present invention: diamond-like carbon (or diamond-like carbon) refers to a film in which diamond and graphite or amorphous carbon are mixed. Materials that are subject to damage in the wild.

The most important feature of the present invention is that the surface of the substrate has an average particle diameter of 1.
The purpose is to polish with abrasive powder of less than μm.

Thereafter, for example, the four methods described above, namely, the X-vacuum deposition method, the chemical vapor deposition method, the plasma chemical vapor deposition method, and the ion beam method may be applied. The base material is polyethylene or polyacetylene.

polytetrafluoroethylene Materials: 1 element each. alloy. Ceramics.

It may be an inorganic material such as glass, or a composite material, but is not particularly limited. Examples of the polishing powder include aluminum oxide, chromium oxide, titanium oxide, silicon carbide, silicon nitride, zirconium oxide, yttrium oxide, and diamond, but are not particularly limited.

Table 1 shows that using a silicon wafer as a substrate, the silicon wafer is polished with aluminum oxide or silicon carbide each having four average particle sizes, and then deposited to a thickness of about 10 μm by the above-mentioned method 2, that is, chemical vapor deposition. The results of measuring the density of a diamond film formed on the surface of a core silicon wafer are shown. To measure the density, after chemically or mechanically peeling the diamond film from the silicon wafer, we use the specific gravity liquid method (prepare several liquids with known specific gravity and different specific gravity, and check whether the diamond film floats in the vaginal fluid. The density of the diamond film is determined based on whether it sinks or sinks, and the error is about 2 factors). As is clear from Table 1, an increase in density occurs. In particular, in the case of abrasive powder with an average diameter of 0.8 μm or less, a marked increase in density is observed.

(Margin below) Table 1 At present, it is not clear why the density increases only with a limited average particle size.

Further, almost the same results as in Table 1 were obtained using other substrates, other abrasive powders, and other forming methods.

Example C of the invention] Molybdenum was used as a substrate, and the surface of the molybdenum was abraded with diamond powder having an average particle size of 0.25 μm. Next, using a mixed gas of methane and hydrogen (volume ratio 1:100) as a reaction gas, plasma chemical vapor deposition using microwaves was applied under conditions of a gas pressure of 40 Torr and a reaction time of 8 hours. A diamond film with a thickness of 10 μm was formed on top of molybdenum.

For comparison, a diamond film with a thickness of 10 μm was formed under the same conditions as above using molybdenum ground with diamond powder having an average particle size of 15 μm as a substrate. When the densities of the two types of diamond films obtained above were measured using the specific gravity liquid method, the density of the diamond film polished with diamond powder with an average particle size of 0.25 μm was 3.117 cm, and the density of the diamond film polished with diamond particles with an average particle size of 15 μm was 3.117 cm. was 2.0 I 7cm". This shows that the diamond film or diamond-like carbon film obtained by the method of the present invention has a high density.

〔Effect of the invention〕

As is clear from the above description, the method of the present invention can easily produce a high-density diamond film or diamond-like carbon film on the surface of a substrate, and has great industrial value.

Agent Patent Attorney Chika Nori Wl Kikuo Takehana

Claims (2)

[Claims] (1) In a manufacturing method for forming a diamond film or a diamond-like carbon film on a substrate, the surface of the substrate is polished with abrasive powder having an average particle size of less than 1 μm, and then a diamond film or a diamond-like carbon film is formed on the substrate. A method for producing a diamond film or a diamond-like carbon film, the method comprising: forming a diamond film or a diamond-like carbon film. (2) The method for producing a diamond film or diamond-like carbon film according to claim 1, wherein the abrasive powder has an average particle size of 0.8 μm or less.