JPS60200898A - Artificial diamond precipitation generator - Google Patents

Abstract

PURPOSE:To prompt deposition and formation of diamond crystal nuclei in the initial stage of reaction by dividing a reaction chamber into an upper chamber for depositing and forming diamond and a lower chamber for performing ion etching, and providing a means for moving a substrate vertically through the upper and the lower chamber. CONSTITUTION:A supporting material 5 mounted with a material S to be worked is moved from a vacuum charging chamber 10 onto a heating device 6 provided to a lower chamber 1B below a vacuum reaction chamber 1 where the material S to be worked is heated. The surface of the material S is activated by ion etching by generating DC glow discharge by impressing a voltage to a glow discharge generating device 8. Then, a shutter 2 is opened and the material S is transferred to an upper chamber 1A with an elevator 7 together with the supporting material 5. While a thermion emitting material 9 is in activated condition, a gaseous mixture consisting of H2 and hydrocarbon is introduced through a reaction gas introducing pipe 3 and activated, and the surface of the material S is heated. By this process, artificial diamond is deposited and formed on the surface of the material S with high deposition and forming rate.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for producing artificial diamond by precipitation.

In the past, many methods have been proposed as methods for producing artificial diamond by precipitation, among them, for example, Japanese Patent Application Laid-Open No. 58-91100
The method using a thermionic emitting material as described in the publication is attracting attention because it allows stable operation with a relatively simple device.

This method using a thermionic emitting material uses, for example, the apparatus shown in the schematic cross-sectional view in FIG. A reaction mixture gas composed of hydrogen is caused to flow downward through a filament C made of metal tungsten as a thermionic emitting material and a material to be treated ei held on a support d, and is exhausted from a reaction gas exhaust pipe f. During this period, the atmospheric pressure in reaction vessel a was maintained at 1 to 300 torr, and filament c'11500 to 2500 torr.
℃ to heat and activate the reaction mixture gas and heat the surface of the material to be treated placed below at a predetermined interval from 300 to 1300℃.
Artificial diamond is precipitated and produced on the surface of the material to be treated 5 by heating the material to a temperature within the range of 1 and allowing a reaction to take place for a predetermined period of time in this state.

However, in this method using a thermionic emitting material, the number of diamond crystal nuclei precipitated on the surface of the material to be treated at the initial stage of the reaction is small, and on the other hand, diamond grows mainly around these crystal nuclei.
Since it takes on the form of a film, a considerable amount of reaction time is required to deposit and form an artificial diamond film having a predetermined thickness.

Therefore, from the above-mentioned viewpoint, the present inventors conducted research to increase the number of diamond crystal nuclei that precipitate on the surface of the treated material at the initial stage of the reaction, and as a result, they decided to add artificial diamond to the surface of the treated material. If the surface is activated by ion etching prior to the formation of the precipitate, the formation of diamond crystal nuclei that precipitate at the initial stage of the reaction will be significantly promoted, resulting in a high rate of precipitate formation. They obtained the knowledge that it is possible to precipitate artificial diamonds.

The present invention provides an artificial diamond precipitation generation device developed based on the above knowledge, which includes a reduced pressure reaction vessel partitioned into an upper chamber where diamond precipitation is performed and a lower chamber where ion etching is performed. and the upper chamber is equipped with a reaction gas inlet pipe, and the lower chamber is equipped with a reaction gas discharge pipe, a shutter that can be opened and closed to partition the reduced pressure reaction container into an upper chamber and a lower chamber, and a shutter of the reduced pressure reaction container. a lifting device for moving the material to be processed up and down across the upper chamber and the lower ice; a heating device for heating the material to be processed in the lower chamber; and ion etching the surface of the material to be processed in the lower chamber. a glow discharge generator necessary for this, and a thermionic emitting material provided at a position facing the surface of the material to be treated that has been moved into the upper chamber of the reduced-pressure reaction vessel.

This apparatus is characterized by a reduced pressure charging chamber and a reduced pressure extraction chamber, which are connected along the outer periphery of the lower chamber of the reduced pressure reaction vessel through gate valves.

Next, the apparatus of the present invention will be specifically described by way of examples with reference to the drawings.

Embodiment FIG. 2 shows a device according to the invention in a schematic cross-sectional view. As shown in the figure, the quartz reduced pressure reaction vessel 1 includes an upper chamber IA for depositing diamond on the surface of the material S to be treated, and a lower chamber IB for performing ion etching on the surface of the material S to be treated. The upper chamber IAi+? : is provided with a reaction gas introduction pipe 3 for introducing into the reduced pressure reaction vessel 1 a reaction mixture gas mainly consisting of hydrocarbon and hydrogen for producing diamond precipitation, and Ar gas for ion etching treatment, and is provided with a reaction gas discharge pipe 4 for discharging these reaction gases.

Further, in the lower chamber IB of the reduced pressure reaction vessel 1, a heating device 6 for heating the material to be treated 84 placed on a support material 5 made of a plate material, a grid material, or a mesh material, and S together with the supporting material in the upper chamber IA (position shown by the two-dot chain line in the figure).
and a lower chamber IB (solid line position in the figure). A high frequency power source or a DC power source 8 as a device for generating discharge is connected.

In addition, in order to make the reaction uniform, a mechanism for rotating the lifting device 7 may be provided as necessary.

Further, in the upper chamber IA of the reduced-pressure reaction vessel L, there is a space opposite to the surface of the treated material S on the support material moved into the upper chamber for the purpose of diamond precipitation and at a position separated by a predetermined pressure.
A thermionic emitting material 9 made of, for example, a metallic tungsten filament is provided.

Furthermore, in the reduced pressure reaction vessel 1, along the outer periphery of the lower chamber IB, the material to be processed S placed on the support material 5 is loaded into the reduced pressure reaction vessel l and taken out from the same. At this time, the reduced pressure charging chamber 1o and the reduced pressure extraction chamber 11 for always maintaining the reduced pressure inside the reduced pressure reaction vessel are connected to the gate valve 1.
2. i3-, and the reduced pressure charging chamber 1o and the reduced pressure extraction chamber 11 each have a gas exhaust pipe 14.
15, and sealing lids 10A and IIA, and further comprising the sealing lids 10A and 11AICld, respectively, a charging rod 1G for moving the treated material S4 on the support material 5 into the reduced pressure reaction vessel, and from the reduced pressure reaction vessel, A take-out frame 17 is provided for taking this out.

Since the device of this invention has the above structure f:, first,
Open the airtight lid 10 Af of the reduced pressure charging chamber 10 and insert the material S to be processed.
i Load the supporting material 5 placed thereon, and close the sealing lid 10A.
After closing and exhausting the gas through the gas exhaust pipe 14 to reduce the pressure in the reduced pressure charging chamber to less than The support material 5 carrying the Si material to be treated is moved onto the heating device 6 provided in the lower chamber by the charging rod 16, and with the gate valve 12 and shutter 2 closed, Ar gas is introduced through the reaction gas introduction pipe 3. is introduced into the reduced pressure reaction vessel l, and on the other hand, the reaction gas is evacuated through the reaction gas discharge pipe 4 to bring the atmospheric pressure to a reduced pressure state of 0.1 to 300 torr. When DC glow discharge is generated on the surface of the material S to be processed by applying it to the glow discharge generator 8 in a state heated to 400 to 500°C by 6, the surface of the material S to be processed is ion etched by this DC glow discharge. 9, the shutter 2 is opened, the lifting device 7 moves the treated material S together with the supporting material 5 into the upper chamber IA,
The spacing between the thermionic radiation material 9 and the surface of the treated material S is 30 to 5.
The temperature of the thermionic emitting material 9 is 1150.
A reaction mixture gas consisting mainly of hydrocarbons and hydrogen is introduced from the reaction gas introduction pipe 3 in a state heated to 0 to 2500°C, and during this time, the reaction mixture gas is activated by the thermionic radiation material 9, and the reaction mixture gas is The surface of material S is 300-13
Since it is heated to a temperature of 00°C, artificial diamonds are precipitated and formed on the surface of the material to be treated S at a significantly high precipitation rate. : After precipitation is generated on the surface of the material to be treated S, the material to be treated Sf is placed in the lower chamber I.
B, the shutter 2 is closed, the gate valve 13 is opened, and the to-be-treated reactor 1 is lowered to the initial loading position in the vacuum chamber 11, together with the supporting material 5, using the extraction frame 17 attached to the airtight lid 11A of the vacuum extraction chamber 11. The sample was moved to the reduced pressure extraction chamber 11, which had been previously evacuated through the gas exhaust pipe 15 and brought into a reduced pressure state, and the sealing lid 11A was opened with the gate valve 13 closed, and the surface of the substrate on which artificial diamond was precipitated was transferred. A series of operations consisting of taking out the treated material s'4 together with the supporting material 5 are performed continuously.

Now, using the above-mentioned apparatus of the present invention, ion etching treatment by ArVc is performed. Material to be treated S: Plane 12.77+l+Il'X Thickness 4.8
Tungsten carbide based cemented carbide (co:
6% by weight, WO: Residue) cutting indexable tip, atmospheric pressure in the reduced pressure reaction vessel 1 1 x 10 to
rr, heating temperature of the material to be treated S by the heating device 6: 500
℃, application type crab 300W to high frequency power source 8 (frequency:
13.56 MHz), treatment time: 10 minutes, reaction mixture gas composition: volume ratio, H2/CH4 = 100
/1, Distance between filament 9 made of metal W as thermionic emitting material and surface of treated material S: 40 mm, Atmospheric pressure in reduced pressure reaction vessel 1 10 torr, Heating temperature of filament 9: 2 ooo C, Reaction time When artificial diamond was precipitated and generated under the following conditions for 6 hours, an artificial diamond film with an average layer thickness of 3 μnt was formed on the surface of the treated material S.

On the other hand, when an artificial diamond film is directly precipitated and formed under the above conditions without performing the above ion etching process, an artificial diamond film with an average layer thickness of only 1.5 μm can be formed. Ta.

As described above, according to the apparatus of the present invention, before precipitating and producing artificial diamond on the surface of the material to be treated, the surface of the material to be treated is subjected to a total ion etching treatment, so that the rate of precipitation and formation of diamond crystal nuclei at the initial stage of the reaction is reduced. This results in industrially useful effects such as the ability to form artificial diamond precipitates at extremely high precipitate formation rates.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view showing a conventional artificial diamond precipitation generating device, and FIG. 2 is a schematic cross-sectional view showing the artificial diamond precipitation generating device of the present invention. In the drawings, 1... reduced pressure reaction vessel, IA... upper chamber, 1B...
Lower chamber, S...material to be treated, 2...shutter, 3.
...Reaction gas inlet pipe, 4...Reaction gas discharge pipe, 5...
Support material, 6. Heating device, 7. Lifting device, 8. High frequency power supply, 9. Thermionic radiation material, 10. Decompression charging chamber, 11. Decompression extraction chamber, 12.13. Gate Pulp, 14.15... Gas exhaust pipe, 10A, IIA... Sealing lid, 16... Charging frame, 17... Taking out frame. Applicant Mitsubishi Metals Co., Ltd. Agent Tomi 1) Kazuo and 1 other person

Claims (1)

[Scope of Claims] A reduced pressure reaction vessel partitioned into an upper chamber where diamond precipitation is performed and a lower chamber where ion etching is performed; the upper chamber is equipped with a reaction gas introduction pipe; a shutter that can be opened and closed and that is equipped with a reaction gas discharge pipe and partitions the reduced pressure reaction container into an upper chamber and a lower chamber; a lifting device that moves the material to be treated up and down across the upper and lower chambers of the reduced pressure reaction container; A heating device for heating the material to be processed in the lower chamber, a glow discharge generating device necessary for ion etching the surface of the material to be processed in the lower chamber, and a heating device for heating the material to be processed in the lower chamber, and a heating device for heating the material to be processed in the lower chamber, and a glow discharge generator for heating the material to be processed in the lower chamber. A thermionic radiation material provided at a position facing the surface of the treated material, and a reduced pressure charging chamber and a reduced pressure extraction chamber connected via a gate valve along the outer periphery of the lower chamber of the reduced pressure reaction vessel. An artificial diamond precipitation generator.