JPH0643279B2 - Vapor phase synthesizer for diamond precipitation - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to tool parts such as cutting tools, wear resistant tools or grinding tools, parts for nuclear reactors represented by the furnace wall of the fusion reactor, heat sinks or speakers. The present invention relates to a vapor phase synthesizing apparatus for diamond precipitation having a thermoelectron radiator which can be used in various industrial fields such as electronic parts such as diaphragms and precision mechanical parts such as cameras and watches.

(Prior Art) As a device for synthesizing diamond from a vapor phase,
Apparatus using sputtering method, apparatus using ion plating method, apparatus combining vapor deposition method and ion implantation method, apparatus using plasma chemical vapor deposition method by microwave or high frequency, and apparatus using thermoelectron emitter and so on.

Among these diamond vapor phase synthesizers, the one using a thermoelectron emitter is capable of continuous production with easy control of the gas in the reflection container, and the diamond obtained by this equipment is homogeneous and of good quality. There is an advantage that it tends to become granular diamond and film diamond.

Japanese Patent Laid-Open Nos. 58-91100 and 60-221395 disclose a diamond synthesizing method using a diamond vapor phase synthesizer equipped with a thermionic radiator.

(Problems to be Solved by the Invention) Japanese Patent Application Laid-Open No. 58-91100 discloses a diamond vapor phase synthesizing method using a diamond vapor phase synthesizing apparatus equipped with a thermoelectron radiator to heat a substrate surface to 500 ° C. to 1300 ° C. The method is characterized by However, this JP-A-58-
The synthesis method by the diamond vapor phase synthesizer disclosed in Japanese Patent No. 91100 has a problem that the deposition rate of diamond is extremely slow. As a solution to this problem, there is JP-A-60-221395. JP-A-60-22
1395 discloses a diamond vapor phase synthesis method using a diamond vapor phase synthesizer equipped with a heating element (thermoelectron radiator), characterized in that a direct current voltage is applied so that the heating element is negative and the substrate is positive. To do. However, JP-A-58-91100 and JP-A-60-2213
In the apparatus disclosed in Japanese Patent Publication No. 95, it is necessary to heat the thermoelectron radiator to as high a temperature as possible, and the substrate is heated by the radiant heat from the thermoelectron radiator heated to this high temperature. If the substrate is excessively heated to a high temperature, there are problems that the substrate is thermally distorted or thermally damaged, and further, the diamond deposition rate becomes slow.

The present invention has solved the above-mentioned problems, and more specifically, a diamond deposition gas in which a substrate heated by radiant heat from a thermoelectron radiator is cooled by a cooling mechanism of a substrate support. The purpose is to provide a phase synthesizer.

(Means for Solving the Problems) The inventors of the present invention tried to deposit diamond on the surface of the substrate by using a diamond vapor phase synthesizer equipped with a thermionic radiator, and the thermionic radiator was high in temperature. It was found that although the amount of excitation gas increased and diamond was more likely to be deposited, the radiant heat from the thermionic radiator increased and the thermal damage to the substrate increased. In addition, it is desirable to bring the substrate as close as possible to the thermionic radiator in order to increase the deposition rate of diamond, but conversely, the substrate is strongly affected by the radiant heat from the thermionic radiator, causing thermal damage as well as the substrate. We have found that it becomes difficult to deposit diamond on the surface. Therefore, as a result of further study, in the diamond vapor phase synthesizer equipped with a cooling mechanism for cooling the substrate, the influence of radiant heat from the thermionic radiator is almost eliminated, and moreover, the deposition of diamond on the substrate surface The present invention has been completed by obtaining the knowledge that the above can be easily achieved.

That is, the vapor phase synthesis apparatus for diamond precipitation of the present invention is provided in a reaction vessel provided with a gas inlet, a thermoelectron radiator installed in the reaction vessel, and a radiant heat region from the thermoelectron radiator. In the diamond vapor phase synthesizing apparatus including the substrate support described above, a cooling mechanism for the substrate support is provided.

The reaction vessel in the vapor phase synthesizing apparatus for depositing diamond of the present invention may have any shape as long as the vessel can adjust the vacuum or gas atmosphere. The thermionic radiator installed in this reaction container is used as a thermal filament or a heating element. Examples thereof include tungsten, molybdenum, tantalum, or those whose surfaces are coated with tungsten carbide, titanium carbide, titanium nitride, or the like, or tungsten carbide. The substrate support disposed in the radiant heat region from the thermionic radiator supports a substrate for depositing diamond and / or diamond-like carbon, and its material is special if it is not deformed by radiant heat. There is no particular limitation, and examples thereof include iron-based alloys such as stainless steel and carbon steel, nickel-based alloys such as Hastelloy and Inconel, and cobalt-based alloys such as stellite.

The cooling mechanism for the substrate support may be any mechanism capable of cooling the substrate supported by the substrate support. For example, the inside of the substrate support is made hollow, and the cavity inside the substrate support is filled with water or liquid. If nitrogen or liquid helium is introduced to cool the substrate while circulating it from the outside of the reaction vessel, the effect of radiant heat from the thermionic radiator is mitigated and the deposition of diamond and / or diamond-like carbon on the substrate surface is promoted. It is what makes me. If the substrate cannot be placed in contact with the surface of the substrate support, a tubular body such as a pipe is provided on the surface of the substrate support, and water, liquid nitrogen or liquid helium is introduced into the tubular body. Then, a mechanism for cooling the substrate may be used. Further, due to the problem of the shape of the substrate or the mass production, the substrate support is moved to the outside of the radiant heat from the thermionic radiator, for example, a plurality of substrates are attached to the rotatably movable substrate support so that the inside of the radiant heat region is outside the region. A mechanism for cooling the substrate supported by the substrate support by rotating the substrate support or a substrate support by introducing water, liquid nitrogen or liquid helium into a tubular body such as a pipe outside the radiant heat region as needed. It is also possible to provide a mechanism for further cooling the substrate supported by.

(Operation) The vapor phase synthesis apparatus for depositing diamond of the present invention is for cooling the substrate for depositing diamond and / or diamond-like carbon, and is provided with a cooling mechanism for cooling this substrate. This is a device in which the precipitation of diamond and / or diamond-like carbon is significantly promoted by the method. In addition, the substrate is an apparatus that is capable of significantly reducing the thermal damage caused by the radiant heat of the thermionic radiator and depositing good quality diamond and / or diamond-like carbon.

(Example) Example 1 A reaction vessel (1) provided with a gas inlet (2) as shown in FIG.
A thermionic radiator (3) made of tungsten, a substrate support (4) arranged in the radiant heat region of the thermionic radiator (3), and a substrate (5) made of Mo on the substrate support (4). ) Is installed, and the inside of the substrate support (4) is made hollow and a mechanism for allowing water to circulate from the cooling water circulator (6) is used. Then, diamond was synthesized under the following conditions.

First, the reaction container (1) is evacuated from the exhaust port (7), and then 99 vo% H ₂ -1 vo% CH ₄ gas is introduced into the reaction container (1) from the gas introduction port (2) to generate thermoelectrons. The temperature of the radiator (3) is set to 2
000 ° C, and the distance between the substrate (5) and thermionic radiator (3) is 3
substrate (5) by circulating water from the cooling water circulator (6) as mm
When diamond was synthesized while cooling, the film-like diamond with high crystallinity was formed in 3 hours in 1 hour on the surface of the substrate.
A μm thickness was obtained. The temperature of the substrate at this time was 980 ° C.

As a comparison, when the above-mentioned vapor phase synthesizing apparatus is used and only the substrate is not cooled by the cooling water circulator and the other conditions are the same as described above, the diamond having a thickness of about 0.3 μm after 1 hour of reaction A film in the form of a film was obtained. The temperature of the substrate at this time was 1400 ° C.

Example 2 A thermoelectron emitter made of tungsten in a reaction vessel (1) provided with gas inlets (2) and (2 ') as shown in FIG.
(3) and a cylindrical substrate support (4) that can be rotationally moved from inside the radiant heat region of the thermionic radiator (3) to outside the radiant heat region, and a substrate made of cemented carbide on the substrate support (4) Install multiple (5),
The cooling mechanism including a pipe-shaped cooling pipe (6 ') and a cooling water circulator (6) capable of circulating water through the cooling pipe (6') is provided outside the radiant heat region of the thermionic radiator. Diamond was synthesized under the following conditions using a vapor phase synthesizer for diamond precipitation.

First, the inside of the reaction vessel (1) is evacuated from the exhaust port (7), and then H ₂ and CH ₄ are separately separated from the gas introduction ports (2) and (2 ′).
9vo% H ₂ -1vo% CH ₄ was introduced, the temperature of the thermionic radiator (3) was 2500 ° C, and the distance between the substrate (5) and thermionic radiator (3) was 3 mm. ) Is positive and the thermionic radiator (3) is negatively applied at 150 V, and cooling is performed by the rotational movement of the substrate support (4) from inside the radiant heat region from the thermionic radiator (3) to outside the radiant heat region. Of the substrate support (4) by a cooling pipe (6 ') provided outside the radiant heat region from the thermionic radiator (3) and a cooling water circulator (6) for circulating water to the cooling pipe (6') When diamond was synthesized while cooling the substrate (5) by a cooling mechanism, granular diamond having high crystallinity was obtained on the surface of the substrate in a thickness of 6.5 μm in 1 hour. The temperature of the substrate at this time was 950 ° C.

For comparison, using the above-mentioned vapor phase synthesis apparatus, when the diamond was synthesized without cooling the substrate by the cooling water circulator and the cooling pipe and cooling the substrate by the rotational movement of the substrate support, the surface of the substrate was In 1 hour, 0.7 μm thick diamond-like carbon was obtained. The temperature of the substrate at this time was 1370 ° C.

Example 3 Diamond was synthesized under the following conditions by the vapor phase synthesizing apparatus for diamond precipitation used in Example 2.

Tungsten thermionic radiator temperature is 2000 ℃, substrate is J
Cemented carbide equivalent to IS standard K10, distance between substrate and thermionic radiator 3 mm, reaction gas concentration 95 vo% H ₂ -5 vo% C
As H ₄ , when the substrate was cooled by the rotational movement of the substrate support, a highly crystalline diamond film having a thickness of 5 μm per hour was obtained on the surface of the substrate.

For comparison, when the diamond was synthesized in the same manner as described above under the other conditions without rotating the substrate support, a 0.5 μm thick film was obtained on the surface of the substrate per hour. The Raman spectroscopic analysis of this film did not show a diamond peak but a graphite peak.

(Effect of the invention) From the above results, the vapor deposition apparatus for diamond precipitation of the present invention has a diamond deposition rate of about 10 times that of the conventional one,
The film-shaped diamond or granular diamond obtained by this apparatus is a high quality crystalline diamond.
In addition, the device of the present invention causes almost no damage to the substrate,
It is stable in quality control, and can be applied to various substrate materials or shapes.

For this reason, the diamond synthesizing device is useful for producing tool materials, reactor parts, electronic parts, precision machine parts, and other parts materials used in various industrial fields that have been conventionally used.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a vapor phase synthesizer for diamond precipitation of the present invention used in Example 1, and FIG. 2 is a vapor phase synthesizer for diamond precipitation of the present invention used in Examples 2 and 3. In the schematic views of FIGS. 1 and 2, 1 is a reaction vessel, 2,
2'is a gas inlet, 3 is a thermoelectron emitter, 4 is a substrate support, 5 is a substrate, 6 is a cooling water circulator, 6'is a cooling pipe, and 7 is an exhaust port.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-60-112698 (JP, A) JP-A-60-127299 (JP, A)

Claims (4)

[Claims] 1. A reaction vessel provided with a gas inlet, a thermoelectron radiator installed in the reaction vessel, and a substrate support provided in a radiation heat region from the thermoelectron radiator. The diamond vapor phase synthesizing apparatus is provided with a cooling mechanism for the substrate support, and the vapor phase synthesizing apparatus for depositing diamond. 2. The cooling mechanism according to claim 1, wherein the inside of the substrate support is hollow and water, liquid nitrogen or liquid helium is introduced into the inside of the substrate support. Vapor phase synthesizer for diamond precipitation. 3. The diamond according to claim 1, wherein the cooling mechanism introduces water, liquid nitrogen or liquid helium into a tubular body provided on the surface of the substrate support. Vapor phase synthesizer for precipitation. 4. The vapor phase synthesizing apparatus for depositing diamond according to claim 1, wherein the cooling mechanism moves the substrate support to the outside of the radiant heat region from the thermionic radiator. .