JP2760837B2 - Diamond coated member and method of manufacturing the same - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a diamond-coated member and a method for producing the same. More specifically, the present invention has sufficient crystallinity and excellent adhesion to a thin-film member. Of a diamond-coated member provided with a coating film made of a diamond and a diamond-coated member capable of efficiently obtaining the diamond-coated member with good reproducibility while improving the film-forming rate of the coating film And how to.

[Prior Art and Problems to be Solved by the Invention] Diamond thin films are excellent in hardness, wear resistance, electrical insulation, thermal conductivity, infrared transmission, solid lubricity and the like. , Abrasive materials, wear-resistant mechanical parts, optical parts, etc., are being used as hard coat materials for various members and electric / electronic materials.

By the way, in order for the diamond-coated member coated with this diamond thin film to exhibit the expected performance,
The adhesion between the thin film member and the thin film must be excellent.

Therefore, various proposals have hitherto been made for the purpose of improving the adhesion between the diamond thin film and the member on which the thin film is formed.

Specifically, various coating members in which an intermediate layer of a metal carbide, a metal nitride, or the like is interposed between the substrate and the diamond layer have been proposed. There is still room for improvement.

Further, Japanese Patent Application Laid-Open No. 62-196371 proposes a coating member in which an outer layer having a crystalline diamond-like structure is formed on a substrate via a layer having an amorphous carbon-like structure.

However, the outer layer of the crystalline diamond-like structure in this covering member may not have sufficient crystallinity,
Desired hardness, wear resistance, etc. may not be obtained.

On the other hand, after an amorphous carbon film is formed on a substrate, a diamond thin film is formed on the amorphous carbon film.
Japanese Patent Application Laid-Open No. 63-277593) and a method of manufacturing a diamond-coated element in which an amorphous diamond film is formed on a substrate subjected to abrasion treatment, and a diamond film is formed on the amorphous diamond film. Etc. have also been proposed.

However, in these methods, since the degree of crystallinity of the diamond film is not quantified, it is not always possible to obtain a coated member provided with a diamond thin film having desired hardness, wear resistance and the like. There is no problem.

Also, a method has been proposed in which the adhesion of a diamond film is improved by changing the concentration of a carbon source gas in the formation of the intermediate layer and the concentration of the carbon source gas in the formation of the outer layer (Japanese Unexamined Patent Publication (Kokai) No. 63-163). 288994, 63-307196, etc.).

However, these methods also do not quantify the degree of crystallinity of the diamond film. Therefore, although it is possible to improve the film formation rate to some extent, diamond having a diamond film having desired properties is used. It has not yet been possible to efficiently manufacture a coated member with good reproducibility.

 The present invention has been made based on the above circumstances.

An object of the present invention is to provide a diamond-coated member having a coating film made of diamond having sufficient crystallinity and excellent adhesion to a thin-film member, and an improvement in the film-forming rate of the diamond-coated member. It is another object of the present invention to provide a manufacturing method which can efficiently obtain a desired reproducibility with good efficiency.

[Means for Solving the Problems] As a result of intensive studies by the present inventors to solve the problems, each of them has a specific crystalline state,
A diamond coating member including a diamond intermediate layer and a diamond layer, each having a specific thickness,
Achieved the present invention by finding that the coating film has excellent adhesion, and that this diamond-coated member can be efficiently obtained with good reproducibility while improving the film forming rate by a specific method. did.

The structure of the invention according to claim 1 includes a diamond layer on a thin film forming member with a diamond intermediate layer interposed therebetween, and a coating film composed of the diamond intermediate layer and the diamond layer has a thickness of 10 μm or less, the diamond intermediate layer diamond layer and each following conditions, the diamond intermediate layer has a thickness d ₁ is 0.2 to 3 .mu.m, a crystalline R <1.0.

{However, the crystalline R is the intensity ratio h ₁ / h ₂ of the Raman spectral intensity, h ₁ is the intensity of the difference [(1550 cm ^-1 and the intensity of the peak intensity and 1000 cm ^-1 of the diamond-like carbon (DLC) )-
(Intensity of 1000 cm ⁻¹ )], and h ₂ is the peak intensity of diamond (intensity of 1332 cm ⁻¹ ). ｝ The diamond layer has a thickness d ₂ of 0.5 to 9 μm and a crystallinity R> 1.2.

(However, the crystallinity R has the same meaning as described above.) A diamond-coated member that satisfies a thickness d ₁ of a diamond intermediate layer <a thickness d _{2 of the} diamond layer. The diamond intermediate layer is formed by a gas phase method using an intermediate layer raw material gas comprising a carbon monoxide gas and a hydrogen gas and having a carbon monoxide gas concentration of 15% or more. Is composed of carbon monoxide gas and hydrogen gas, and the concentration of carbon monoxide gas is
2. The method for producing a diamond-coated member according to claim 1, wherein the diamond-coated member is formed by a vapor phase method using a diamond layer raw material gas of 12% or less.

As shown in FIG. 1, for example, the diamond-coated member according to the first aspect is provided with a coating film 4 composed of a diamond intermediate layer 2 and a diamond layer 3 on a thin-film member 1.

The material of the thin film forming member is not particularly limited, for example, silicon, aluminum, titanium, tungsten, molybdenum, cobalt, vanadium, chromium,
Metals such as niobium; metal oxides such as SiO ₂ , Al ₂ O ₃ and WO; SiC,
Metal carbides such as WC and TiC; metal nitrides such as Si ₃ N ₄ , TiN and AlN; and alloys and ceramics thereof.

There is no particular limitation on the shape of the thin film forming member, and any shape such as a plate, a bar, a cone, a chip (a triangle, a square, etc.), and a special shape such as a drill can be used. It is.

The diamond intermediate layer formed on the thin film forming member has a peak intensity of diamond-like carbon (DLC) in Raman spectrum as shown in FIG.
The difference between the intensity of 000cm ^-1 [(strength of 1550cm ^-1) - (1000cm
Strength of ^-1)] h ₁ and the diamond peak intensity (1332 cm ^-1
Crystallinity R defined by the ratio h ₁ / h ₂ to the strength h ₂
It is less than 1, preferably 0.9 or less. If the crystallinity R is 1 or more, the adhesion to the thin film-formed member may not be sufficient.

The thickness of the diamond intermediate layer is 0.2 to 3 μm, preferably 0.2 to 2 μm.

The diamond intermediate layer can be formed by employing, for example, a gas phase method.

Specifically, by bringing a gas obtained by exciting a source gas containing a carbon source gas into contact with the thin-film member provided in the reaction chamber, the diamond intermediate layer is formed on the thin-film member. Obtainable.

The source gas may contain at least a carbon source gas, but is preferably a gas containing at least a carbon atom and a hydrogen atom, and particularly preferably a gas containing a carbon atom, a hydrogen atom and an oxygen atom.

Specifically, the source gas may be, for example, a mixed gas of a carbon source gas and a hydrogen gas.

If desired, a carrier gas such as an inert gas can be used together with the raw material gas.

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

Examples of the hydrocarbon compound include paraffinic hydrocarbons such as methane, ethane, propane, and butane; ethylene,
Olefin hydrocarbons such as propylene and butylene; acetylene hydrocarbons such as acetylene and allylene; diolefin hydrocarbons such as butadiene; alicyclic hydrocarbons such as cyclopropane, cyclobutane, cyclopentane and cyclohexane; cyclobutadiene, benzene , Toluene, xylene, aromatic hydrocarbons such as naphthalene; methyl chloride,
Examples thereof include halogenated hydrocarbons such as methyl bromide, methylene chloride, and carbon tetrachloride.

Examples of the oxygen-containing compound include ketones such as acetone, diethyl ketone and benzophenone; alcohols such as methanol, ethanol, propanol and butanol;
Ethers of methyl ether, ethyl ether, ethyl methyl ether, methyl propyl ether, ethyl propyl ether, phenol ether, acetal, cyclic ethers (dioxane, ethylene oxide, etc.); acetone, pinacolin, methyl oxide, aromatic ketones (acetophenone, benzophenone) Ketones such as diketone and cyclic ketone; aldehydes such as formaldehyde, acetaldehyde, butyraldehyde, and benzaldehyde; organic acids such as formic acid, acetic acid, propionic acid, succinic acid, butyric acid, oxalic acid, tartaric acid, and stearic acid; Acid esters such as methyl acetate and ethyl acetate; dihydric alcohols such as ethylene glycol and diethylene glycol;
Examples thereof include carbon monoxide and carbon dioxide.

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

The carbon source gas is not a simple substance, but a fourth class dangerous substance specified by the Fire Service Law; a first petroleum such as gasoline, and a second petroleum such as kerosene, turpentine oil, camphor oil and pine oil. Also, gases such as third petroleum such as heavy oil, and fourth petroleum such as gear oil and cylinder oil can be used. Further, the above-mentioned various carbon compounds may be used as a mixture.

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

The hydrogen gas is not particularly limited, for example, gasification of petroleum, conversion of natural gas, water gas, etc., electrolysis of water,
A product obtained by a reaction between iron and steam, a complete gasification of coal, or the like, which is sufficiently purified can be used.

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

This atomic hydrogen has an effect of removing non-hard carbon such as graphite-structured carbon which is precipitated simultaneously with the precipitation of hard carbon.

As means for exciting the source gas, for example, microwave plasma CVD, RF plasma CVD, DC plasma CV
D method, hot filament method, thermal CVD method, light CVD method, combustion flame method, sputtering method and the like can be mentioned.

Among these, various plasma CVD methods (including a magnetic field CVD method) are preferable.

The diamond layer formed on the diamond intermediate layer has the crystallinity R> 1.2, preferably R> 1.3, and more preferably R> 1.5. If the crystallinity is 1.2 or less, properties such as hardness and abrasion resistance may decrease.

The thickness of the diamond layer is 0.5 to 9 μm,
Preferably it is 1 to 9 μm.

The diamond layer can be formed by suitably employing, for example, a gas phase method, similarly to the diamond intermediate layer.

In the diamond-coated member according to claim 1,
The sum (d ₁ + d ₂ ) of the thickness d ₁ of the diamond intermediate layer and the thickness d _{2 of the} diamond layer is 10 μm or less, preferably 8 μm or less.
μm or less. When the sum exceeds 10 μm, film peeling tends to occur.

Moreover, the the thickness d ₂ of the diamond intermediate layer thickness d ₁ and the diamond layer, it is necessary to satisfy the relationship d ₁ <d _2. When d ₁ ≧ d ₂ , in the coating film composed of the diamond intermediate layer and the diamond layer, the property of the diamond intermediate layer becomes more dominant than the property of the diamond layer, and thus the hardness of the coating film And properties such as wear resistance may be reduced.

In the diamond-coated member according to claim 1,
Since the crystallinity of each of the diamond intermediate layer and the diamond layer is quantified, and the thickness of each of the diamond intermediate layer and the diamond layer is defined, the diamond intermediate layer is in contact with the thin film forming member. The diamond layer has properties required for the diamond layer, such as hardness and abrasion resistance, while ensuring the desired adhesion.

Therefore, the diamond-coated member according to claim 1 is, for example, a cutting tool, an abrasive, a wear-resistant mechanical part,
It can be suitably used as a hard coat material for various members such as optical parts and electric / electronic materials.

The diamond-coated member according to the first aspect having the above-mentioned features is efficiently manufactured under the good reproducibility while improving the film forming rate by the manufacturing method according to the second aspect described in detail below. Can get better.

In the manufacturing method according to claim 2, the thin film is formed by a gas phase method using a source gas for an intermediate layer comprising a carbon monoxide gas and a hydrogen gas and having a carbon monoxide gas concentration of 15% or more. The diamond intermediate layer is formed on a member.

Specifically, the intermediate layer raw material gas is introduced into the reaction chamber in which the thin film forming member is installed, and a gas obtained by exciting the intermediate layer raw material gas is brought into contact with the thin film forming member. Thereby, the diamond intermediate layer can be obtained on the thin film formation member.

The material and shape of the thin film member to be used are the same as the material and shape of the thin film member according to the first aspect.

The intermediate layer raw material gas is a mixed gas of carbon monoxide gas and hydrogen gas, and the concentration of carbon monoxide gas is 15% or more, preferably 20% or more. When the concentration of the carbon monoxide gas is lower than 15%, the content of diamond-like carbon in the diamond intermediate layer obtained by using the intermediate layer raw material gas decreases, so that the thin film forming member and the diamond intermediate layer May not have sufficient adhesion.

The means for exciting the intermediate layer raw material gas is not particularly limited as long as a diamond intermediate layer containing diamond-like carbon can be formed by a gas phase method. Method, plasma decomposition by high-frequency induction discharge, plasma decomposition by microwave discharge (including magnetic field CVD method), or ion beam method in which plasma decomposition is performed in an ion chamber or ion gun and ions are extracted by an electric field Alternatively, any of a pyrolysis method (including an EACVD method) in which pyrolysis is performed by heating with a hot filament, a combustion flame method, a sputtering method, and the like can be employed.

In these methods, the reaction usually proceeds under the following conditions to form an intermediate diamond thin film on the thin film forming member.

That is, since the temperature of the surface of the thin film member varies depending on the means for exciting the intermediate layer raw material gas, it cannot be unconditionally determined, but is usually 350 to 1,200 ° C., and preferably 500 to 1,100 ° C. . For example, when the plasma CVD method is used, 700 to 1,000 ° C. is preferable.

When the temperature is lower than 350 ° C., the deposition rate of the intermediate layer diamond thin film deposited on the thin film forming member may be reduced, or a film containing a large amount of non-diamond components may be deposited. On the other hand, if the temperature is higher than 1,200 ° C., the effect corresponding thereto cannot be achieved, which is disadvantageous in terms of energy efficiency, and the formed diamond intermediate layer may be etched.

The reaction pressure is usually 10 ^-6 to 10 ³ torr, preferably 10 ^-5 t
orr to 760 torr.

If necessary, with a magnetic field applied to the reaction chamber,
The intermediate layer raw material gas can also be excited. Therefore, in this case, a magnetic field-CVD method can be suitably used as the means for exciting the intermediate layer source gas, and for example, the area for forming the intermediate layer diamond thin film can be increased.

If the reaction stress is lower than 10 ^-6 torr, the deposition rate of the diamond thin film forming the diamond intermediate layer may be slow or the diamond thin film may not be deposited.

On the other hand, if it is higher than 10 ³ torr, the corresponding effect may not be obtained.

The reaction time cannot be determined unconditionally because it varies depending on the temperature of the surface of the thin film member, the reaction stress, the required film thickness, and the like. However, the reaction time can usually be set within 5 hours.

The diamond thin film intermediate layer thus formed has a thickness d ₁ of 0.1 to 3 μm, preferably 0.2 to 2 μm, and the crystallinity R is R <1.0, preferably R <0.9.

In the method according to the second aspect of the present invention, the method further comprises the steps of:
% Of the diamond layer is formed on the diamond intermediate layer by a gas phase method using a diamond layer raw material gas of not more than 10%.

Specifically, the raw material gas for the diamond layer is introduced into a reaction chamber in which the thin film forming member formed with the diamond intermediate layer is installed, and a gas obtained by exciting the raw material gas for the diamond layer is obtained. By bringing the diamond intermediate layer into contact with the diamond intermediate layer, the diamond layer can be obtained on the diamond intermediate layer.

The diamond layer raw material gas is a mixed gas of carbon monoxide gas and hydrogen gas, and the concentration of carbon monoxide gas is 12% or less, preferably 10% or less. If the concentration of the carbon monoxide gas exceeds 12%, the crystallinity of the obtained diamond layer is reduced, and the desired hardness and wear resistance may not be obtained.

The means for exciting the source gas for the diamond layer is not particularly limited as long as the diamond layer can be formed by a vapor phase method, and the excitation of the source gas for the intermediate layer in the formation of the diamond intermediate layer is not limited. Any of the methods that can be adopted for the present invention can be suitably adopted.

In the formation of a diamond layer, the reaction usually proceeds under the following conditions.

That is, the temperature of the surface of the diamond intermediate layer is:
Since it depends on the means for exciting the source gas for the diamond layer, it cannot be unconditionally determined, but is usually 350
To 1,200 ° C, preferably 500 to 1,100 ° C. For example, when the plasma CVD method is used, 700 to 1,000 ° C. is preferable.

When the temperature is lower than 350 ° C., the deposition rate of the diamond film deposited on the diamond intermediate layer may be reduced, or a film containing a large amount of amorphous diamond may be deposited. On the other hand, even if it is higher than 1,200 ° C,
The effect corresponding thereto is not exhibited, which is disadvantageous in terms of energy efficiency, and the formed diamond layer may be etched.

The reaction pressure is usually 10 ^-6 to 10 ³ torr, preferably 10 ^-5 t
orr to 760 torr.

If necessary, with a magnetic field applied to the reaction chamber,
The source gas for the diamond layer can also be excited. In this case, a magnetic field CVD method can be suitably adopted as the means for exciting the source gas for the diamond layer.

If the reaction pressure is lower than 10 ^-6 torr, the deposition rate of the diamond thin film may be slow, or the diamond thin film may not be deposited.

On the other hand, if it is higher than 10 ³ torr, the corresponding effect may not be obtained.

The reaction time is the temperature of the surface of the diamond intermediate layer,
Since it differs depending on the reaction pressure, the required film thickness, and the like, it cannot be unconditionally determined, but usually it can be within 5 hours.

The diamond layer thus formed has a thickness d ₂
Is 0.5 to 9 μm, preferably 1 to 8 μm, and the crystallinity R is R> 1.2, preferably R> 1.3, and more preferably R> 1.5.

The sum (d ₁ + d ₂ ) of the thickness d ₁ of the diamond intermediate layer and the thickness d _{2 of the} diamond layer formed as described above is 10 μm or less, preferably 8 μm or less, and d ₁ < it is d _2.

According to the method of the second aspect, the diamond-coated member according to the first aspect is provided with a coating film made of diamond having sufficient crystallinity and excellent adhesion to the thin-film member. The film can be efficiently manufactured with good reproducibility while improving the film forming speed of the cover film.

In the present invention, the diamond intermediate layer is not necessarily required to be a single layer. For example, an intermediate layer having different crystallinity may be used in multiple layers, and if the surface layer is crystalline diamond, the diamond intermediate layer may be used. May be, for example, three or four layers.

[Examples] Next, examples of the present invention and comparative examples will be shown, and the present invention will be described more specifically.

(Example 1) Formation of diamond intermediate layer WC-6 whose surface was previously scratched with diamond abrasive grains
A plate made of% Co cemented carbide was used as a thin film forming member and installed in a reaction chamber of a microwave plasma CVD apparatus.

Next, 25 SCCM of carbon monoxide gas was introduced into the reaction chamber.
Then, hydrogen gas was introduced at 75 SCCM, respectively, and the output of the microwave power supply with a frequency of 2.45 GHz was set to 300 W under the conditions of a pressure of 40 torr in the reaction chamber and a temperature of the thin film-formed member of 900 ° C.

Under these conditions, plasma treatment by microwave discharge method
Performed for 30 minutes.

After completion of the reaction, the plate with the thin film was taken out of the reaction chamber, and the thin film was subjected to Raman spectroscopic analysis to obtain a crystalline R ₁ = 0.85
Was confirmed.

 The thickness of this thin film was about 1.5 μm.

Formation of diamond layer Then, the plate material with the thin film was placed in the reaction chamber, and plasma was generated by microwave discharge under the same conditions as above except that carbon monoxide gas was introduced at 5 SCCM and hydrogen gas was introduced at 95 SCCM. The treatment was performed for 60 minutes.

After the reaction is completed, the diamond-coated member is removed from the reaction chamber, and the thin film is subjected to Raman spectroscopic analysis to determine the crystallinity.
It was confirmed that R ₂ = 1.74. The total thickness of the thin film on the thin film member is about 4.2 μm.

No film peeling was observed in the diamond-coated member thus obtained.

When the surface hardness of the diamond-coated member was measured using a micro hardness tester (MVK-10, manufactured by Akashi Seisakusho), no indentation by a Vickers indenter was observed, and 10 ⁴ kg /
It was estimated that the hardness was about mm ² .

 Table 1 shows the reaction conditions and results.

(Example 2) In Example 1, the carbon monoxide gas was changed to 25 SCCM.
Instead of introducing hydrogen gas into the reaction chamber at 75 SCCM, carbon monoxide gas at 30 SCCM and hydrogen gas at 70 SCCM
The procedure was the same as in Example 1 except that each of the components was introduced into the reaction chamber by CM.

 Table 1 shows the reaction conditions and results.

Example 3 Formation of Diamond Intermediate Layer In the formation of Example 1, the carbon monoxide gas was used.
Instead of introducing hydrogen gas into the reaction chamber at 25 SCCM and 75 SCCM, respectively, introducing carbon monoxide gas at 40 SCCM and hydrogen gas at 60 SCCM into the reaction chamber, and reducing the reaction time from 30 minutes to 20 minutes A diamond intermediate layer was formed in the same manner as in Example 1 except for the change.

Formation of Diamond Layer Next, in Example 1, carbon monoxide gas was supplied at 5 SCCM, hydrogen gas was supplied at 95 SCCM, and hydrogen gas was supplied at 7 SCCM, and hydrogen gas was supplied at 93 SCCM. , While being introduced into the reaction chamber,
A diamond layer was formed in the same manner as in Example 1 except that the reaction time was changed from 60 minutes to 70 minutes, to obtain a diamond-coated member.

 Table 1 shows the reaction conditions and results.

(Comparative Example 1) WC-6 whose surface has been previously scratched with diamond abrasive grains
A plate made of% Co cemented carbide was used as a thin film forming member and installed in a reaction chamber of a microwave plasma CVD apparatus.

Next, 5 SCCM of carbon monoxide gas was introduced into the reaction chamber.
Then, hydrogen gas was introduced at 95 SCCM, respectively, and the output of the microwave power supply at a frequency of 2.45 GHz was set to 280 W under the conditions of a pressure of 40 torr in the reaction chamber and a temperature of the thin film-formed member of 900 ° C.

Under these conditions, plasma treatment by microwave discharge method
This was performed for 120 minutes to produce a diamond-coated member.

 Table 1 shows the reaction conditions and results.

Comparative Example 2 In Comparative Example 1, carbon monoxide gas was supplied at 5 SCCM.
Instead of introducing hydrogen gas at 95 SCCM into the reaction chamber, carbon monoxide gas at 30 SCCM and hydrogen gas at 70 SCCM
Comparative Example 1 except that each was introduced into the reaction chamber.
A diamond-coated member was prepared in the same manner as described above.

 Table 1 shows the reaction conditions and results.

(Comparative Example 3) Formation of Diamond Intermediate Layer In Example 1, the reaction time was changed from 30 minutes to 60 minutes.
A diamond intermediate layer was formed in the same manner as in Example 1 except that the time was changed to minutes.

Formation of Diamond Layer Next, a diamond layer was formed in the same manner as in Example 1 except that the reaction time was changed from 60 minutes to 20 minutes to obtain a diamond-coated member.

 Table 1 shows the reaction conditions and results.

(Comparative Example 4) After forming a diamond intermediate layer in the same manner as in Comparative Example 3, the reaction time was reduced to 60 in Example 1.
A diamond coating member was obtained by forming a diamond layer in the same manner as in Example 1 except that the time was changed from 180 minutes to 180 minutes.

 Table 1 shows the reaction conditions and results.

(Evaluation) As is clear from Table 1, the diamond-coated member according to claim 1 manufactured by employing the method according to claim 2 has an improved adhesion between the coating film and the thin-film member. Excellent,
It was confirmed that there was no film peeling and that the hardness of the coating film was high.

[Effects of the Invention] (1) According to the invention of claim 1, the crystallinity of each of the diamond intermediate layer and the diamond layer is quantified, and the film pressure of each of the diamond intermediate layer and the diamond layer is defined. The diamond intermediate layer reliably achieves the desired adhesion to the thin film-formed member, and the diamond layer has the advantage of always having the properties required for the diamond layer such as hardness and abrasion resistance. A covering member can be provided.

(2) According to the second aspect of the present invention, a diamond intermediate layer is formed by a gas phase method using an intermediate layer raw material gas comprising carbon monoxide gas and hydrogen gas and having a carbon monoxide gas concentration of 15% or more. After that, when the concentration of the carbon monoxide gas is 12% or less, the diamond layer is formed by a vapor phase method using a diamond layer raw material gas, so that the above-mentioned advantages are obtained. It is possible to provide an industrially useful method for producing a diamond-coated member that can efficiently obtain the diamond-coated member according to the first aspect with good reproducibility while achieving a structure of a film forming rate.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of the diamond-coated member of the first aspect of the present invention, and FIG. 2 is an explanatory view showing an example of Raman spectrum measurement. 1 ... thin film member, 2 ... diamond intermediate layer, 3
…… Diamond layer, 4 …… Coating film

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-62-196371 (JP, A) JP-A-62-241898 (JP, A) JP-A-63-288994 (JP, A) JP-A-63-1988 277593 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C30B 28/00-35/00

Claims (2)

(57) [Claims] A diamond layer is provided on a thin film forming member with a diamond intermediate layer interposed therebetween, and a coating film composed of the diamond intermediate layer and the diamond layer has a thickness of 10 μm or less. It said diamond layer and each following conditions, the diamond intermediate layer has a thickness d ₁ is 0.2 to 3 .mu.m, a crystalline R <1.0. {However, the crystalline R is the intensity ratio h ₁ / h ₂ of the Raman spectral intensity, h ₁ is the intensity of the difference [(1550 cm ^-1 and the intensity of the peak intensity and 1000 cm ^-1 of the diamond-like carbon (DLC) )-
(Intensity of 1000 cm ⁻¹ )], and h ₂ is the peak intensity of diamond (intensity of 1332 cm ⁻¹ ). ｝ The diamond layer has a thickness d ₂ of 0.5 to 9 μm and a crystallinity R> 1.2. (However, the crystallinity R has the same meaning as described above.) A diamond-coated member, wherein the thickness d ₁ of the diamond intermediate layer is smaller than the thickness d _{2 of the} diamond layer. 2. The method according to claim 1, wherein the diamond intermediate layer is formed by a gas phase method using an intermediate layer raw material gas comprising a carbon monoxide gas and a hydrogen gas and having a carbon monoxide gas concentration of 15% or more. 2. The diamond layer according to claim 1, wherein the diamond layer is formed by a gas phase method using a source gas for a diamond layer comprising a carbon monoxide gas and a hydrogen gas and having a carbon monoxide gas concentration of 12% or less. A method for producing a diamond-coated member.