JPH02267268A - Production of diamond coated member - Google Patents

Abstract

PURPOSE:To form the diamond film with a good adhesive property at a high film forming speed on a base body by exciting a gaseous raw material contg. gaseous carbon monoxide, gaseous hydrogen and base body-constituting element contg. gas and bringing the same into contact with the base body, thereby forming an intermediate layer. CONSTITUTION:The gaseous raw material contg. the gaseous carbon monoxide, the gaseous hydrogen and the base body-constituting element-contg. gas is excited to an active gas and this gas is brought into contact with the base body to form the intermediate layer. The concn. of the gaseous carbon monoxide is adjusted to about 1 to 80vol.%, the concn. of the gaseous hydrogen to about 10 to 98.9vol.% and the concn. of the base body constituting element contg. gas to 0.1 to 10vol.%. The pressure in a reaction device is regulated to about 10<-6> to 800Torr, the base body temp. to about 350 to 1200 deg.C, and the reaction time to about 1 minute to 5 hours. The gaseous raw material is supplied at about 10 to 100sccm and the thickness of the intermediate layer is regulated to about 0.1 to 5mu. The diamond film is formed on this intermediate layer, by which the diamond coating layer having the high adhesive property is obtd. at the high film forming speed.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a method for manufacturing a diamond-coated member having a laminated structure, and more specifically, to a method for producing a diamond-coated member having a high adhesion to an S body. The present invention relates to a method of manufacturing a diamond-coated member that can be formed at film speeds.

[Prior Art and Problems to be Solved by the Invention] Diamond thin films have excellent hardness, wear resistance, electrical insulation, thermal conductivity, infrared transparency, solid lubricity, etc., and are therefore used, for example, in cutting tools. It is used as a heart coat material for various parts such as abrasives, abrasion-resistant mechanical parts, and optical parts, as well as electrical and electronic materials.

However, in order for a diamond-coated member coated with this diamond thin film to exhibit the desired properties, the thin film must have excellent adhesion to a substrate such as metal, alloy, or ceramic.

However, conventional diamond-coated members still have room for improvement in this respect.

Therefore, in order to improve the adhesion between the diamond film and the substrate, various proposals have been made to interpose an intermediate layer such as metal carbide or metal nitride between the thin film and the substrate.
In addition to not necessarily achieving sufficient effects, there is also the problem that manufacturing is difficult.

On the other hand, JP-A-61-106494 discloses a coating member in which a diamond thin film is formed on a substrate via an intermediate layer having a substrate component and a carbon component, and a method for manufacturing the same. Furthermore, according to this publication, in order to improve the adhesion between the diamond layer and the substrate,
a, group 6a metal or Si, or carbide thereof,
It is described that an intermediate layer of nitride or solid solution is provided.

Furthermore, Japanese Patent Application Laid-Open No. 61-163273 discloses a member in which at least one of the coating layers on the surface of the substrate is a diamond layer containing Si.

However, the techniques disclosed in the above-mentioned publications generally use methane gas or the like as a carbon source gas for forming the intermediate layer, and the concentration of the gas is very low, resulting in a slow film formation rate and also causing the carbonization reaction of Si. There is a problem that the effect of improving adhesion is not sufficient. Therefore, if the concentration of the methane gas is increased in order to increase the film-forming rate, it becomes difficult to form a mixed crystal of diamond in the intermediate layer, causing another problem in that it is impossible to obtain a diamond layer with high adhesion.

An object of the present invention is to provide a method for manufacturing a diamond-coated member that can obtain a diamond coating layer having excellent adhesion to a substrate and having desired performance at a high deposition rate.

[Means for Solving Problem This method of manufacturing a diamond-coated member is characterized in that an intermediate layer is formed by bringing gas into contact with a substrate, and a diamond film is formed on the intermediate layer.

This invention will be explained in more detail below.

-Substrate- Any substrate can be used as long as it is possible to form a diamond layer on the surface of the substrate used to form the diamond-coated member. Depending on the purpose, an appropriate material can be selected from among various substrates known for forming the material.

As said substrate, metals such as silicon, manganese, vanadium, thallium, aluminum, titanium, tungsten, molybdenum, germanium and chromium,
These oxides, nitrides and carbides, their alloys,
A1.03-Pe system, TiC-Ni system, TiC-Co
Examples include cermets such as cermets such as cermets based on B-type, B-Fe type, and various types of ceramiuxes.

Further, when this diamond-coated member is used for carbide tools such as cutting tools, examples of substrates that can be suitably used include, for example.

WC-Co alloy, @C-Tie-Cg alloy, WC-
TiC-TaC-Co alloy, WC-TiN-Co alloy, WC-Tie-TiN-C.

Examples include cemented carbide alloys such as alloys.

Among these cemented carbides, those with a Co content of 1 to 30% by weight are particularly preferred, and Si3N4. S
iC, 5iO1, TiC, A-view, 03, or.

A sintered body made of a mixture of these is also preferred.

Further, when this diamond-coated member is used as a circuit board in the electronics field, examples of the substrate include a silicon wafer or a processed product thereof.

These substrates may be subjected to surface treatments to further improve their adhesion to the vapor phase synthesized diamond film, such as
It may be subjected to a washing process or a scratching process.

There are no particular restrictions on the shape of the base, or if this diamond-coated member is to be used as a tool, the shape of the base may be matched to the shape of various tools.

1. Formation of intermediate layer - In the method of the present invention, an active gas obtained by exciting a raw material gas containing carbon monoxide gas, hydrogen gas, and a gas containing an element constituting the substrate is applied to the surface of the substrate. By contacting, an intermediate layer is formed.

The carbon monoxide is not particularly limited, and for example, sufficiently purified generator gas or water gas obtained by hot reaction of coal, coke, etc. with air or steam can be used.

What should be noted here is that if methane gas or the like is used instead of carbon monoxide as a raw material gas component, an intermediate layer containing diamond and carbides of the elements constituting the substrate will not be formed.

There are no particular restrictions on the hydrogen gas, and hydrogen gas that can be obtained, for example, by gasification of petroleum, metamorphosis of natural gas, water gas, etc., electrolysis of water, reaction of iron with steam, complete gasification of coal, etc. is sufficient. It can be used after being purified.

Hydrogen constituting the hydrogen gas is excited to form atomic hydrogen.

This atomic hydrogen has the effect of removing non-diamond components such as graphite and amorphous carbon that are deposited simultaneously with the precipitation of diamonds.

Examples of the gas containing the elements constituting the substrate include hydrides and halides of the elements constituting the substrate, and more specifically, 5iHn, WF, Ti.
Can list C sentences such as 4.

Further, it is important to consider the combination of the type of the substrate and the source gas, and some preferred specific examples of combinations of the substrate and the source gas are as follows.

Substrate Raw material gas Sr 5ill, + co+ H*SiO SiH4+ CO+ HaSi3N4Sil1
4+ CO+ HtSiCsiL+ co+ Hz Ca-Co IFF, + CO+
H.

TiCTiCJl, +co+H.

In addition, in this invention, other gases such as CH, etc. may be partially used in combination with carbon monoxide as a carbon source. Further, it is also possible to add to the above raw material gas a gas that produces the same substance as the substrate, for example, N2 when the substrate is composed of Si and N4.

The concentration of each of the above-mentioned components in the lX material gas is usually 1 to 3% by volume for carbon monoxide gas, preferably 3 to 30% by volume for hydrogen gas, and preferably 10 to 98.9% by volume for hydrogen gas. is 65 to 96.9% by volume, and the gas containing the base element is usually 0.1 to 10% by volume.
, preferably 0.1 to 5% by volume.

There are no particular limitations on the excitation means for the raw material gas, such as plasma decomposition using DC or AC arc discharge, high frequency induced discharge, plasma decomposition using microwave discharge (magnetic field-CVD method). ), or ion beam method in which plasma decomposition is carried out in an ion chamber or ion gun, and ions are extracted by electrolysis, thermal decomposition method (CEACVD method, in which pyrolysis is performed by heating with a hot filament), combustion flame method, and sputtering method. Any of these can be adopted. In the gas phase method, the raw material gases may be introduced into the reaction chamber by mixing carbon monoxide gas, hydrogen gas, and the element-containing gas from the beginning, or by introducing these gases individually. They may be mixed within the reaction chamber.

Note that other reaction conditions for forming the intermediate layer can be set according to conditions for forming a normal diamond thin film.

For example, the pressure within the reactor is typically 10-'Torr.
~800 Torr, and the substrate temperature is typically 3
50℃～1. Within the range of Zoo℃, the reaction time is 1 minute to 5 minutes.
set to time.

Further, the feed rate of the raw material gas is usually 1 to 10.
1,000 sec m, preferably 20~
It is SOOsecm.

The concentration of the constituent elements of the substrate in the intermediate layer formed as described above cannot be determined unconditionally depending on the type of substrate and the thickness of the diamond layer.
It is usually 0.1 to 10% by weight, preferably 0.1 to 5% by weight. If the concentration is out of the range, the adhesion of the diamond layer tends to deteriorate. Note that the concentration of the element constituting the base body does not necessarily have to be uniform throughout the entire thickness of the intermediate layer; for example, it is also preferable to gradually reduce this concentration from the base surface.

The thickness of this intermediate layer differs depending on the type of substrate and the thickness of the diamond layer and cannot be determined unconditionally, but it is usually 0.1 to 57 tm, preferably [1,1 to 3 ILm]. It is. The thickness is 0.1)
If it is less than bm, the adhesion of the diamond layer will not be increased, and if the thickness exceeds 5 gm, the effect proportional to the increase in thickness may not be achieved.

The thickness of this intermediate layer also correlates with the thickness of the diamond layer, and if the coefficient of thermal expansion between this intermediate layer and the diamond layer is significantly different, the total thickness of this intermediate layer and the diamond layer must be less than 1Opm. It is preferable to set vRfrJ so that the thickness of the intermediate layer is thinner than the thickness of the diamond layer.If the thickness of the intermediate layer is greater than the thickness of the diamond layer, the hardness and wear resistance of the diamond layer can be sufficiently ensured. There are times when you will not be able to do anything.

- Formation of Diamond Layer - After forming the intermediate layer on the substrate as described above, a diamond layer is formed on the intermediate layer by a vapor phase method.

The method for forming this diamond layer is not particularly limited, and any known method may be adopted. For example, an active gas obtained by exciting a raw material gas containing a carbon source gas and a hydrogen gas is The intermediate layer is formed by contacting the intermediate layer with the substrate placed in the reaction chamber.

As the carbon source gas, gases such as various hydrocarbons, halogen-containing compounds, oxygen-containing compounds, and nitrogen-containing compounds can be used.

Examples of hydrocarbon compounds include paraffinic hydrocarbons such as methane, ethane, propane, and butane; olefinic hydrocarbons such as ethylene, propylene, and butylene; acetylenic hydrocarbons such as acetylene and arylene; and diolefinic hydrocarbons such as butadiene. Alicyclic hydrocarbons such as hydrogen dichloropropane, cyclobutane, cyclopentane, and cyclohexane; Aromatic hydrocarbons such as cyclobutadiene, benzene, toluene, xylene, and naphthalene; Methyl chloride, methyl bromide, methylene chloride, carbon tetrachloride, etc. Examples include halogenated hydrocarbons.

Examples of the halogen-containing compound include halogenated hydrocarbons such as halogenated methane, halogenated ethane, and halogenated benzene.

Examples of oxygen-containing compounds include ketones such as acetone, diethyl ketone, and benzophenone; alcohols such as methanol, ethanol, propatool, and butanol; methyl ether, ethyl ether, ethyl methyl ether, methyl propyl ether, ethyl propyl ether,
Ethers such as phenol ethers, acetals, and cyclic ethers (dioxane, ethylene oxide, etc.): Ketones such as acetone, vinacolin, methyl oxide, aromatic ketones (acetophenone, benzophenone, etc.), diketones, and cyclic ketones: formaldehyde, acetaldehyde,
Aldehydes such as butyraldehyde and benzaldehyde; organic acids such as formic acid, acetic acid, propionic acid, succinic acid, acetic acid, oxalic acid, tartaric acid, and stearic acid; methyl acetate,
Acid esters such as ethyl acetate; dihydric alcohols such as ethylene glycol and diethylene glycol; carbon monoxide and carbon dioxide.

Examples of the nitrogen-containing compound include amines such as trimethylamine and triethylamine.

In addition, the carbon source gas may be a single substance or a class 4 hazardous substance stipulated in the Fire Service Act; a class 1 petroleum such as Kallin, or a class 2 petroleum such as kerosene, turpentine, ginger oil, pine oil, etc. Gases such as tertiary petroleum oils such as , heavy oil, and quaternary petroleum oils such as gear oil and cylinder oil can also be used. It is also possible to use a mixture of the various carbon compounds mentioned above.

Among these carbon source gases, paraffin hydrocarbons such as methane, ethane, and propane, which are gases or have high vapor pressure at room temperature; or ketones such as acetone and penzophenone, alcohols such as methanol and ethanol, carbon monoxide, and dioxide. Oxygen-containing compounds such as carbon gas are preferred, and carbon monoxide is particularly preferred.

As for the hydrogen gas, the same gas as used in forming the intermediate layer can be used.

When a mixed gas of carbon monoxide gas and hydrogen gas is used as this raw material gas, for example, the proportion of carbon monoxide gas is usually 1% by volume or more, preferably 3% by volume or more.

If this ratio is less than 1% by volume, a diamond layer may not be obtained.

The amount of the raw material gas supplied into the reaction chamber varies depending on the content of the carbon source gas in the raw material gas and whether the reaction system is a continuous system or a discontinuous system. Not possible, but usually 10~t, ooo SC
CM, preferably 20 to 5003 CCM.

The surface temperature of the substrate in the reaction chamber when forming the diamond layer, more precisely the surface temperature of the intermediate layer, is usually 35 (1~!, 200°C, preferably 600 S).
-1,100°C.

If this temperature is lower than 350° C., the precipitation rate of diamond deposited on the intermediate layer may be slowed down, or a diamond layer containing a large amount of non-diamond components may be formed. On the other hand, if the temperature exceeds 1,200° C., the diamond layer deposited on the intermediate layer is etched away, and no improvement in the diamond precipitation rate may be observed.

The reaction pressure in the reaction chamber is usually 1 to 10-'.
0'torr, preferably 10-'~10''torr
r, particularly preferably lO-cohe 800 torr
It is.

If the reaction pressure is lower than 10-'torr, the diamond precipitation rate may be slow or diamond may not be precipitated. on the other hand.

Even if it exceeds 10'torr, the corresponding effect may not be achieved.

The reaction time cannot be determined unconditionally because it varies depending on the temperature, reaction pressure, required layer thickness, etc.

The thickness of this diamond layer varies depending on the type of substrate, but is generally 0.01 μm or more, preferably 0.05 μm or more.
Desirable range is ~100#Lm, thickness is 0.01I
A diamond layer thinner than Lm may have insufficient chemical and physical properties to act as a diamond thin film, and a diamond layer thicker than 1100p may require a very long time to form.

1. Diamond-coated member - The diamond-coated member manufactured in this manner is characterized in that the intermediate layer contains the carbide of the base constituent element and diamond, and that carbon monoxide is used as a carbon source for forming the intermediate layer. The adhesion between the substrate and the diamond coating film is improved due to the fact that the concentration can be made higher than when CI (4, etc.) is used, and carbide formation is easy.

[Example] Next, examples and comparative examples of the present invention will be described.

(Example 1) A plate material made of Si as a base was subjected to microwave plasma CV
It was installed inside the reaction chamber of D device.

Then, SiH, gas 't 1 sec.
.

CO gas 7 sec, H* gas 101005e
The output of the microwave power source with a frequency of 2.45 GHz was set to 400 W under the conditions that the pressure inside the reaction chamber was 40 torr and the plate temperature was 900° C.

Under these conditions, plasma treatment using the microwave discharge method was performed for 3
This was done for 0 minutes.

After the reaction was completed, the plate material with the intermediate layer formed on its surface was bubbled out of the reaction chamber, and the thickness of the intermediate layer was measured, and it was found that it was approximately 1.81 hours.
It was m. When a thin film formed on a plate under the same conditions as above was analyzed by Auger analysis and micro X-ray diffraction, it was confirmed that SiC was about 45% by volume and diamond was about 55% by volume.

Next, the plate material with this intermediate layer formed on the surface was installed in the reaction chamber, and CO gas was applied for 7 seconds and Hz gas was applied for 93 seconds.
Plasma treatment was performed for 60 minutes under the same conditions as above except that cc- was introduced. the result.

A diamond layer was formed on the surface of the intermediate layer, and the total thickness was about 4.1 pm. Raman spectroscopic analysis of the surface of the diamond-coated member thus obtained revealed that 133
Only a sharp peak was observed at 2 cm-', and no amorphous component was observed.

Further, when the surface hardness of this diamond-coated member was measured using a hardness meter (manufactured by Akashi Seisakusho; ^V to 1^■), no scratches caused by the diamond indenter (50 kg load) were observed.

(Comparative Example 1) Using the same plate material as in Example 1 as a substrate, the formation of the intermediate layer was omitted and a diamond layer was directly formed on the surface of the plate material in the following manner.

That is, Table 1 shows six reaction conditions and results in which a diamond layer was formed on the surface of the plate material under the same conditions as in the example except that the plasma treatment was performed for 120 minutes.

(Example 2) The base material was made of SiC, plasma treatment was performed for 20 minutes when forming the intermediate layer, and the flow rate of CO gas was set at 5 seconds when forming the diamond layer.
A diamond-coated member was manufactured under the same conditions as in Example 1 except that the flow rates of m and H gas were set to 95SCC-.

The reaction conditions and results are shown in Table 1.

(Example 3) The plate material as the base was made of W C-Co, and W F s was used instead of SiH4 gas in the reaction chamber during the formation of the intermediate layer.
Example 1 except that the gas was introduced at 2 sec.
Table 1 shows the reaction conditions and results for producing a diamond-coated member under the same conditions.

(Comparative Example 2) When forming the intermediate layer, CH gas was introduced into the reaction chamber instead of CO gas at 25 ec-, and the flow rate of 5iHn gas was 0.
1 scc layer, plasma treatment was performed for 100 minutes when forming the intermediate layer, and CH gas was added to the reaction chamber for 1 sec instead of CO gas when forming the diamond layer.
, and plasma treatment was performed for 120 minutes.
Table 1 shows the reaction conditions and results for manufacturing a diamond-coated member under the same conditions as in Example 2 except for the following.

(Hereinafter, blank spaces) Table 1 As is clear from Table 1, the diamond-coated member produced by the method of the present invention has excellent adhesion between the coating film and the substrate, and there is no layer peeling. Furthermore, the hardness of the coating layer is high and the time required to form one layer is short, that is, it can be manufactured at a high film formation rate.

[Effects of the Invention] According to the manufacturing method of the present invention, carbon monoxide is used as the carbon source for forming the intermediate layer, so unlike the conventional method using methane gas etc., the intermediate layer can be manufactured at a high film formation rate. can.

Further, in the manufacturing method of the present invention, an intermediate layer containing carbide of the element and diamond is formed using a raw material gas consisting of carbon monoxide, hydrogen, and a gas containing an element constituting the substrate. This increases the adhesion of the diamond layer formed on the intermediate layer. Furthermore, the diamond layer has a large height and has good wear resistance.

Therefore, the present invention can provide diamond-coated members suitable for various industrial fields such as cutting tools, abrasives, wear-resistant mechanical parts, optical parts, electrical and electronic materials, etc., with high productivity.

Claims (1)

[Claims] (1) An active gas obtained by exciting a raw material gas containing carbon monoxide gas, hydrogen gas, and a gas containing elements constituting the substrate is brought into contact with the substrate to form an intermediate layer, and an intermediate layer is formed on the intermediate layer. A method of manufacturing a diamond-coated member, comprising forming a diamond film.