JPH02188495A - Production of thin film of diamond or the like - Google Patents

Abstract

PURPOSE:To improve the adhesion and uniformity in thickness of the thin film by exciting a raw gas contg. a gaseous carbon source, and bringing the obtained gas into contact with a member having a protrusion on which the thin film is to be formed in the presence of an auxiliary member. CONSTITUTION:The member 1 having a protrusion 10 on which a thin film is to be formed is held on a support 20, and the tip of the auxiliary member 2 is set at the distance of <=5mm from the protrusion 10. The reaction chamber is kept at 10<-6>-10<3>Torr, the member 1 is kept at 300-1300 deg.C, the raw gas consisting of 0.1-90% gaseous carbon source (e.g. methane) and H2 is supplied at the flow rate of 1-1000SCCM, the gas obtained by exciting the raw gas with the plasma produced from a microwave oscillator is brought into contact with the member 1, and a diamond film and/or a diamondlike carbon film are formed.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for producing a diamond-based thin film, and more specifically, the present invention relates to a method for producing a diamond-based thin film, and more specifically, a method for manufacturing a diamond-based thin film, and more specifically, a method for producing a diamond-based thin film, and more specifically, a method for producing a diamond-based thin film, and more specifically, a method for producing a diamond-based thin film, and more specifically, a method for producing a diamond-like thin film. Thin films and/or diamond-like carbon thin films can be deposited with good reproducibility and stability, for example, on special shaped +8I films with minute edges such as microtrills and cutting tools.
v The present invention relates to a method for producing a diamond-like thin film, which allows the formation of a YQ film consisting of a diamond thin film and/or a diamond-like carbon thin film while easily controlling the film forming conditions for a member to be formed.

[Prior art and problems to be solved by the invention] In recent years,
Many attempts have been made to improve the cutting performance and life of cutting tools such as micro drills by coating them with diamond thin films and/or diamond-like carbon thin films.

In order to coat cutting tools such as micro drills with a diamond thin film and/or diamond-like carbon thin film to improve cutting performance and service life, it is necessary to It is necessary to imitate a diamond thin film and/or a diamond-like carbon thin film having an excellent and uniform thickness.

In other words, if the film thickness is non-uniform, a sudden change in thermal stress or internal stress occurs, and the diamond-like thin film is likely to peel off, making it impossible to obtain a cutting tool with a diamond-like film that has the desired cutting performance and life. I can't find anything similar.

Therefore, various proposals have been made for forming a diamond-like thin film of uniform thickness on cutting tools.

For example, in JP-A No. 63-166733, a substrate on which metals or metal compounds thereof are uniformly dotted is placed in a reaction tank, the substrate is heated to 500 to 1300°C, and then the substrate is placed in the reaction tank. A method for manufacturing a diamond film is disclosed in which a diamond-forming gas containing at least hydrogen atoms, carbon atoms, and oxygen atoms is introduced and the gas is activated to deposit diamond on the surface of the substrate.

However, according to this method, when the substrate is a flat member such as a flat cutting tip, the substrate temperature is controlled uniformly by external heating or cooling, and a diamond film of uniform thickness is formed. Although it is possible to some extent to form a Since it is difficult to maintain uniformity, it is not possible to form a diamond film with a uniform thickness.

Therefore, in the above method, when the substrate is a non-flat member, it is necessary to employ a method of internally heating the member, such as microwave heating or high-frequency heating, in order to keep the temperature of the five members uniform. For this reason, the microwave plasma CVD method, which simultaneously achieves member heating and plasma generation, is an extremely excellent method for application to these members.

However, in this method, if the output of the microwave plasma is lowered, it will not be possible to form a diamond film, and if the output of the microwave plasma is increased, the plasma will be locally concentrated at the edge of the member on which the thin film is to be formed. As this part becomes abnormally high temperature, the film thickness in the high temperature part becomes thicker, and the film thickness becomes uneven overall, making it substantially difficult to form a thin film or causing damage to the material on which the thin film is formed. It becomes impossible to form a diamond film with excellent adhesion, and the film swells. In addition, depending on the degree of convexity, the actual situation is that the convex portion of the member on which the thin film is formed may melt.

In other words, in the conventional diamond film manufacturing method that employs the vapor phase method, for example, the s
If the IgB forming member is non-flat and convex, FJI! ! ! There is a problem in that it is difficult to form a diamond film that has excellent adhesion to the member to be formed and excellent uniformity of the film H with good reproducibility and stability.

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

The purpose of the present invention is to provide QJ! ! 2. A diamond-like thin film that has excellent adhesion to the member on which it is formed and has a uniform thickness.
The vapor phase method allows film formation with good reproducibility and stability, and is particularly suitable for specially shaped parts with convex parts (microscopic edges) such as drills and cutting tools. J & Diamond thin Ig while easily controlling film conditions!
and/or to provide a method for producing a diamond-like fi1 film that can uniformly form a high-quality coating film made of a diamond-like carbon thin film.

[Means for Solving the Problems] As a result of intensive studies by the present inventors to solve the above-mentioned problems, the present inventors have found that in the production method of a diamond thin film employing a vapor phase method, in the presence of a specific auxiliary member. For example, when a thin film forming member having a convex portion (hereinafter sometimes simply referred to as a thin film forming member) is brought into contact with a gas obtained by exciting a raw material gas containing a carbon source gas, a thin film is formed. Even if the member to be formed has a minute end, such as a micro drill, it is possible to effectively prevent local concentration of plasma on the end of one member, and it is possible to prevent the thin film from adhering to the member to be formed. We have discovered that it is possible to efficiently form a diamond M film and/or a diamond-like carbon thin film with excellent properties and uniform thickness with good reproducibility and stability, while easily controlling the film formation conditions. As a result, we have arrived at the present invention.

The configuration of the present invention is to pump a gas obtained by exciting a raw material gas containing a carbon source gas in the presence of an auxiliary member installed close to the convex part of a thin film forming member having a convex part. This is a method for producing a diamond thin film, characterized in that a diamond film and/or a diamond-like carbon film is formed on the thin film forming member by bringing it into contact with the Q deliquid forming member.

In the method of the present invention, a raw material gas containing a carbon source gas is introduced into a reaction chamber.

The raw material gas to be used may contain at least a carbon source gas, but preferably contains at least carbon atoms and hydrogen atoms, and preferably contains carbon atoms, hydrogen atoms, and nitrogen atoms. Gases are particularly preferred.

Specifically, examples of the raw material gas include a mixed gas of a carbon source gas and hydrogen gas, and an oxygen-containing hydrocarbon compound gas.

Further, if desired, a carrier gas such as an inert gas may be used together with the raw material gas.

As the carbon source gas, gases such as various hydrocarbons, oxygen-containing compounds, nitrogen-containing compounds, etc. 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; diolefinic hydrocarbons such as butadiene; Hydrogen didichloropropane, cyclobutane.

Alicyclic hydrocarbons such as cyclopentane and cyclohexane;
Examples include aromatic hydrocarbons such as cyclobutadiene, benzene, toluene, xylene, and naphthalene; halogenated hydrocarbons such as methyl chloride, methyl bromide, methylene chloride, and carbon tetrachloride.

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; alpha 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; ethylene glycol,
Examples include dihydric alcohols such as diethylene glycol, carbon dioxide, 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 gasoline, a class 2 petroleum such as kerosene, turpentine oil, pine oil, pine oil, etc. It is also possible to use gases such as tertiary petroleum oils such as heavy oil, tertiary petroleum oils such as gear oil and cylinder oil. 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 benzophenone, alcohols such as methanol and ethanol, carbon oxide, and carbon dioxide. Oxygen-containing compounds such as carbon gas are preferred.

There are no particular restrictions on the hydrogen gas, and hydrogen gas obtained, for example, by gasification of petroleum, metamorphosis of natural gas, water gas, etc., electrolysis of water, reaction between iron and 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-hard carbon, such as graphite-structured carbon, which is precipitated at the same time as hard carbon is precipitated.

The total stoichiometric amount of the raw material gas is usually 1 to 1.0003C
(:M, preferably IO to ZOOSCCM.

Further, when a mixed gas of carbon source gas and hydrogen gas is used as the raw material gas, the mixing ratio of carbon source gas and hydrogen gas is usually 1 to the total flow rate of carbon source gas and hydrogen. The flow rate of the carbon source gas is 0.1 to 90%, preferably 0.2 to 80%, and more preferably 0.2 to 60%.

If the flow rate of the carbon source gas in the mixed gas is less than 0.1%, a diamond-based thin film may not be formed, or even if a diamond-based thin film is formed, the deposition rate will be extremely low.

There are no particular restrictions on the material of the vJ film forming rod-shaped member used in the method of the present invention, and examples thereof include silicon, aluminum, titanium, tungsten, molybdenum,
Metals such as cobalt and chromium, their oxides, nitrides and carbides, their alloys, IC-Co series, wC-T
iC=Go series, cemented carbide such as WC-TiC-TaC-Co series, AIJ3- Fe series, TiC-Ni series, Ti
Any cermet selected from C--Co, TiC--TiN, B, C--Fe, and other types of glasses, ceramics, resins, etc. can be used.

Furthermore, in the method of the present invention, by performing film formation in the presence of an auxiliary member, which will be described in detail later, local concentration of plasma can be effectively prevented. The shape of the forming member is also not particularly limited as long as it has a convex end; for example, it may be a round bar shape or a square bar shape.

Any shape can be used, such as a rod shape such as a cone shape, a pyramid shape, a vibrator shape, a drill shape, or a flat plate shape having a convex portion. In any case, the method of the present invention can be suitably applied to plasma concentration which cannot be prevented by the conventional holding member provided on the outer periphery of the withdrawal forming member.

In particular, when the thin film forming member is a cutting tool such as a trill or a dental tool, the thin film forming member formed with a diamond thin film and/or diamond-like carbon [1] obtained by the method of the present invention, It can be used as is as a cutting tool or dental tool.

Examples of such tools include solid trills,
Suitable examples include drilling tools such as micron drills, tips with special shapes for general lathes, cutters, etc.; various cutting tools such as end mills and bits; and dental tools such as dental drills and skelatch bars.

In the method of the present invention, in the presence of an auxiliary member provided close to the convex part of the 11i film forming member having the convex part, the convex part of the 9 deliquing forming member is , bringing into contact the gas obtained by exciting the source gas,
A diamond thin film and/or a diamond-like carbon thin film is formed on the rod-shaped member on which the thin film is to be formed.

That is, in the method of the present invention, as shown in FIG. 1, for example, in a microwave plasma CVD apparatus,
It is important to hold the liquid removal forming member 1 having the convex portion 10 on the support stand 20 and to provide the auxiliary member 2 close to the convex portion 10.

Here, "close" means a distance that can effectively disperse the plasma near the convex part 1Q of the thin film forming member l, and fi the convex part lO of the thin film forming member l and the auxiliary member 2. The distance from the end of the base is usually within 5 mm, preferably within 3 mm. If this distance exceeds 5 mm,
Depending on the auxiliary member 2, the convex portion lO of the thin film forming member 1
It may not be possible to effectively prevent plasma from concentrating locally.

The auxiliary member 2 installed as described above, for example, as shown in FIG.
It has the function or effect of preventing local concentration of plasma.

The material for forming the auxiliary member 2 having such functions and actions is not particularly limited, and examples include metals such as silicon, aluminum, titanium, tungsten, molybdenum, cobalt, and chromium, and oxides, nitrides, and carbides of these metals. , these alloys, W (nee Co-based, WC-Ti
Cemented carbide such as C-Co type, WC-TiC-TaC-Co type, etc. can be suitably used.

For example, the member on which the thin film is formed is WC-C.

system, WC-Tic-Go system, WC-TiC-TaC-G
When the auxiliary member is made of a cemented carbide such as an o-based cemented carbide, it is not possible to form the auxiliary member with a material having the same or similar physical properties as the material for forming the thin film member, such as using such a cemented carbide. Preferably, in the manufacturing method of the present invention, the material forming the auxiliary member is a material having the same or similar physical properties, particularly thermal and electrical properties, as the material forming the thin film forming member having the convex portion. This is because local concentration of plasma can be more effectively prevented. Therefore, it is preferable to select a combination of materials having similar dielectric constants.

Further, as the form of the material forming the auxiliary member, a material suitable for the shape of the member on which the thin film is formed can be selected and used from among forms such as a wire, a net, a plate, and a bar. .

Specifically, for example, when the member on which the thin film is to be formed is microtrill, T& material or net material can be preferably used, and wire material can be particularly preferably used.

In the method of the present invention, by installing the auxiliary member as described above, it is possible to prevent plasma from locally concentrating on the edge of the thin film forming member, and to prevent plasma from locally concentrating on the edge of the thin film forming member. A thin diamond film and/or diamond film with excellent adhesion and uniform thickness prevents melting and thickening of the film.
Alternatively, a diamond-like carbon thin film can be produced.

The means for exciting the raw material gas is not particularly limited as long as it can form a diamond g film and/or a diamond-like carbon thin film by a vapor phase method, such as plasma decomposition by direct current or alternating current arc discharge. method, plasma decomposition method using high frequency induced discharge,
Method of plasma decomposition by microwave discharge (ECR-
(including the CVD method), an ion beam method in which plasma decomposition is performed in an ion chamber or an ion gun, and ions are extracted by an electric field, and a thermal decomposition method (including the EACVD method), in which the ions are thermally decomposed by heating with a hot filament. can also be adopted. Among these various excitation means, it is particularly effective to employ the microwave plasma C/VD method and the high frequency plasma CVD method.

In the method of the present invention, the reaction proceeds under the following conditions, and the f! A diamond-like thin film with excellent adhesion to the I-film coating member and excellent uniformity of film thickness is deposited.

That is, in the method of the present invention, the temperature of the thin film-formed member is usually set at 300 to 1,300°C, preferably 500 to 1,100°C.

If this temperature is lower than 300° C., the precipitation rate of the diamond thin film may be slowed down, or a film containing a large amount of hard carbon may be formed. On the other hand, even if the temperature is higher than 1:100°C, no commensurate effect will be achieved and this will be disadvantageous in terms of energy efficiency.

In the method of the present invention, in the film forming step,
Although the temperature of the member on which the thin film is to be formed may be changed within the above range, it is usually preferable to keep it constant within the above range. In particular, by keeping the temperature distribution of the thin film forming member constant within the above range, it is possible to obtain a diamond-like H film with even better adhesion to the thin film forming member and uniformity of film thickness.

The reaction pressure is usually 10-' to 10' torr, preferably 1 G-' torr to 760 torr.

In addition, in the method of the present invention, one reaction pressure is 1 torr.
When setting the value lower than , it is preferable to excite the raw material gas while applying a magnetic field within one reaction chamber. Therefore, in this case, the ECR is used as the excitation means for the raw material gas.
(Electron cyclotron)-CVD method can be suitably employed.

If the reaction pressure is lower than 10-'torr, the deposition rate of the diamond-like thin film may be slowed or the diamond-like thin film may not be deposited.

On the other hand, even if it is made higher than 103 torr, the effect commensurate with that may not be achieved.

The reaction time cannot be determined in part because it varies depending on the temperature of the member on which the thin film is to be formed, the reaction pressure, the required film thickness, etc. Therefore, the optimum time may be selected as appropriate.

According to the method of the present invention, even if the member to be formed with a thin film has minute edges such as microtrills, it is possible to prevent plasma from locally concentrating on these edges and cause abnormal heat generation. , we can efficiently produce high-quality diamond-based thin films with excellent adhesion and uniform thickness without abnormal film formation, with good reproducibility and stability, and by easily controlling film-forming conditions. It can be manufactured.

The diamond-based thin film obtained in this way is not only particularly suitable for use in cutting tools such as cutting tools and dental tools, but also for use in specially shaped wear-resistant mechanical parts having convex portions, etc. It can be suitably used as a hard coating material for various parts, electronic materials, etc.

[Example] Next, an example of the present invention and a comparative example will be shown to further specifically explain the present invention.

(Example 1) A mini-drill for drilling holes in printed circuit boards (JIS KIOφ=2.0) having a We-6%Co composition was installed in the reaction chamber of a microwave plasma CVD apparatus as a thin film forming member, and the end of this mini-drill was Part 2■11r
Diameter 1 with 1 gap. An auxiliary member consisting of DI tungsten wire was installed as shown in FIG.

Next, a mixed gas consisting of 5% -carbon oxide and 95% hydrogen gas was introduced into the reaction chamber at a flow rate of 101005e, and the frequency was increased under the conditions of the pressure in the reaction chamber of 40 torr and the temperature of the thin film forming member of 900°C. 2.45Gllz
Microwave M, the output of the source was set to 70W.

Under these conditions, plasma treatment using the microwave discharge method was performed for 6 days.
Over time, we manufactured a mini drill for drilling holes in printed circuit boards with thin films.

Note that the member for forming a thin film, which was made of a mini-trill for drilling holes in printed circuit boards, was used after being washed.

After the reaction was completed, the obtained 61H printed circuit board drilling drill was taken out of the reaction chamber and the thin film was subjected to Raman spectroscopy, and a sharp peak due to diamond was observed at a position of 1333 csi.

In addition, the film thickness of each part of this thin film is 4 to 4.5 pm,
It had excellent uniformity.

(Example 2) In Example 1, the flow rate of the mixed gas was set to 100 scc.
In addition to changing the speed from ■ to 50 seconds, the member temperature was increased to 90 seconds.
(Execution was carried out in the same manner as in Example 1 except that the temperature was changed from 1°C to 950°C.

After the reaction is complete, take out the obtained mini-trill for drilling holes in printed circuit boards with thin film from the reaction chamber.

When Raman spectroscopy was performed on the thin film, 133
A sharp peak due to diamond was observed at a position of 3 csi-'.

Further, the film thickness of each part of this FIH was 7 to By-m, and had excellent uniformity.

(Comparative Example 1) In the same manner as in Example 1, frj
We manufactured a mini drill for drilling holes in printed circuit boards with membranes.

When the obtained mini-drill for drilling holes in a printed circuit board with a thin film was taken out from the reaction chamber and Raman spectroscopic analysis was performed on the thin film, a sharp peak due to diamond was observed at a position of 13:13 cm-'.

Furthermore, the film thickness of each part of this thin film is 0 to 7 μm, and there are some parts where the thin film is not formed, so compared to the thin film of the mini drill for drilling holes in printed circuit boards with a diamond thin film obtained in Examples 1 and 2. It was not only non-uniform but also susceptible to 'AgI.

(Evaluation) From the results of Example 1, Example 2, and Comparative Example 1, it was confirmed that according to the method of the present invention, diamond FIJWJ with excellent adhesion to the thin film member and uniformity of film thickness could be obtained. did.

[Effects of the Invention] According to the present invention, (1) A carbon source gas is introduced in the presence of an auxiliary member installed close to the convex portion of a thin film forming member having a convex portion (fine end portion). Since the gas obtained by exciting the raw material gas contained therein is brought into contact with the member on which the thin film is formed, even if the member on which the thin film is to be formed has a minute end, such as a microdrill, there will be no damage near the end. (2) Therefore, uniform plasma can uniformly heat the l8Iv forming member. This prevents the convex parts from melting due to overheating or thickening the film due to abnormal film formation, resulting in a diamond thin film with excellent adhesion to the member on which the thin film is formed and uniform film thickness. and/or can form a diamond-like carbon thin film, and (3) has excellent reproducibility and stability, and can easily control film-forming conditions. It is possible to provide an industrially useful method for producing a diamond-like thin film, which has the following advantages: it is possible to form a Wi film made of a high-quality diamond-like thin film also on a forming member.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an example of the relationship between the i8M film-formed member and the auxiliary member when microwave plasma CVD equipment is used in the manufacturing method of the present invention, and FIG. FIG. 3 is an explanatory diagram showing a dispersion state of plasma near an end. 1... Thin film formed member, 2... Auxiliary member. 10... Convex portion Figure 1 Figure 2 Procedure amendment

Claims (1)

[Claims] (1) A gas obtained by exciting a raw material gas containing a carbon source gas is applied to the thin film coating in the presence of an auxiliary member installed close to the convex part of the thin film forming member having a convex part. A method for producing a diamond-like thin film, comprising forming a diamond film and/or a diamond-like carbon film on the thin film forming member in contact with a forming member.