WO2010092996A1 - Process for the production of diamond materials - Google Patents

Abstract

Diamond materials, particularly, diamonds having any shapes can be produced at a low cost by processing a large number of raw materials of various kinds at once using a large-sized reactor. Diamond materials are deposited, formed, and grown by subjecting carbonaceous materials in which hydrogen remains to hot isostatic pressing. The carbonaceous materials may contain, as necessary, diamond-forming additives in various forms and shapes. The carbonaceous materials themselves function as the reactors and as the sources of hydrogen and hydrocarbon; and thus diamonds can be produced using general-purpose hot isostatic pressing equipment even at a pressure as low as about 0.2GPa.

Description

Method for producing diamond material

The present invention relates to an electrodeposition grindstone, a polishing / processing related member such as a polishing slurry, a high temperature semiconductor, a high voltage semiconductor, a high frequency semiconductor, a power semiconductor, an electron emission device such as a panel display, a light emitting element, a laser element, a light detecting element, The present invention relates to a method for producing a diamond material that can be suitably used for strain detection elements, pressure detection elements, temperature detection elements, magnetic field detection elements, heat sinks, sensor electrodes, battery electrodes, various devices, and the like.

Carbon is a liquid at 4000 ° C and 15 GPa or more, but when it is cooled to about 3000 ° C while maintaining pressure, it changes from a liquid state to solid diamond. Therefore, extremely high temperature and high pressure conditions were necessary to produce diamond from molten carbon. Natural diamonds are presumed to have been reduced in the presence of a catalyst, such as carbonate melts moving and concentrated in the mantle.

(High temperature high pressure method)
In the late 19th century, Moissan, France, tried to synthesize diamond by rapidly quenching molten iron and carbon. At the same time, in Scotland, Hanney announced that diamonds were synthesized by the high-temperature and high-pressure method.
In 1955, GE in the United States announced that it had synthesized artificial diamond by melting carbon and iron using a belt-type anvil furnace, and then announced that ASEA and De Beers joint mine succeeded in synthesizing diamond. did. In any of these methods, ultrahigh pressure treatment of 5 to 10 GPa was performed in the temperature range of 1200 to 2400 ° C.

In 1962, Toshiba succeeded in synthesizing industrial diamond grains at a temperature of 800 ° C. and a pressure of 6 GPa using germanium and nickel as catalysts. Even now, industrial diamonds are produced under the same conditions using such catalysts.

(Shock method)
A method of synthesizing diamond with explosive pressure has also been implemented. In this method, an explosive is used to generate a blast of 4000 to 5000 m / sec, and the metal tube is made to collide with a metal tube filled with a material mixed with carbon, iron, or copper metal powder at a speed of about 2000 m / sec. . This generates a shock wave in the material, and part of the carbon is converted to diamond. Also in this manufacturing method, it is said that a pressure of 10 GPa or more and a temperature of about 3000 ° C. are instantaneously applied, and it is applied to the manufacture of fine diamond powder for polishing. A method of producing a large-scale explosion in an inert atmosphere such as underwater explosion, ice, nitrogen, carbon dioxide, etc. has also been implemented.

(Vapor phase growth method)
In 1952, Eversole in the United States deposited diamond by vapor phase growth using diamond seed crystals, and in 1976 Soviet Spitsyn and Derjagin et al. Confirmed the deposition of diamond on a substrate other than diamond. Since this discovery, methods such as the chemical transport reaction method, hot filament method, combustion flame method, microwave plasma method, and high-frequency plasma method have been devised and applied to diamond coating on tools, etc., and devices have been developed using diamond thin films. It is.

(Thermal excitation method)
One of the vapor phase growth methods is the hot filament method and the combustion flame method. In the combustion flame method, hydrocarbons thermally excited to about 3000 ° C. in a reducing flame of acetylene and oxygen combustion flame are deposited on a cooled substrate.
In the hot filament method, methane and hydrogen are thermally excited to about 2000 ° C. by a hot filament on the top of the substrate, and diamond is deposited on the substrate at a low temperature. Used for coating diamond tools.

(Halogen promotion method)
Hydrocarbon and fluorine, alcohol and fluorine are passed through a reaction tube heated to about 900 ° C., and diamond is deposited on a substrate maintained at a temperature lower by about 200 ° C. Compared to the thermal excitation method, it can be manufactured at a low temperature, but the diamond formation rate is extremely low.

(Plasma excitation method)
In this method, plasma is generated by microwaves, high frequency, DC voltage, etc. and excited. As the reaction gas, methane or hydrogen is generally used, and diamond is deposited in a thin film at a substrate temperature of 300 to 1000 ° C. The pressure is in the range of about 0.1 to 200 Torr, and the substrate is silicon, tantalum, tungsten, molybdenum, gold, copper, aluminum, graphite, silica glass, sapphire, tungsten carbide, titanium carbide, silicon carbide, magnesium oxide, etc. in use.

Electrodeposition grindstones, polishing and processing related materials such as polishing slurries, high temperature semiconductors, high voltage semiconductors, high frequency semiconductors, power semiconductors, electron emission devices such as panel displays, light emitting elements, laser elements, light detection elements, strain detection elements, Conventional methods for manufacturing artificial diamond used for pressure sensing elements, temperature sensing elements, magnetic field sensing elements, heat sinks, sensor electrodes, battery electrodes, and other devices, as well as ornaments, are low in productivity and high in cost. There was a problem.

There are high-temperature and high-pressure methods and impact methods to synthesize granular, massive, and powdered diamonds, but it is necessary to create a high-pressure state of several GPa, and the manufacturing equipment must be made of a strong material that can withstand high pressure. Therefore, the actual reaction space was small, and as a result, it was forced to manufacture with extremely low productivity. Since the growth rate is mainly determined by the temperature gradient in the molten metal, inclusion is likely to occur when the growth rate exceeds the limit, and the upper limit of the growth rate is about 0.01 carat per hour, approximately 2 mg.

Diamond thin film has thermal conductivity, dielectric strength, heat resistance, corrosion resistance, strong radiation resistance, X-ray absorption characteristics similar to the human body, affinity for biological substances, inertness to chemical substances, excellent electrical characteristics, high mobility It has excellent characteristics such as dielectric breakdown electric field and small dielectric constant, and is expected to be applied to ideal heat sink, radiation, X-ray monitor, biosensor, chemical electrode, power device, high frequency device, etc. The growth rate was slow, from several microns to several tens of microns, making it difficult to stably manufacture large shapes. The plasma CVD equipment and hot filament equipment used for the production of thin films, as well as the production speed, require a reaction chamber such as vacuum and atmosphere adjustment, but the thin film is produced only on the substrate surface, and multiple substrates It was difficult to manufacture by laminating. For this reason, although it has excellent characteristics, there have been limitations on the practical use of diamond thin films industrially.

The production equipment and conditions are individually designed according to the shape of the diamond to be produced, that is, the shape of a thin film, block, etc., the crystal orientation of 100, 111, etc., the crystal form of polycrystal, single crystal, homoepitaxial, heteroepitaxial, etc. Therefore, it was difficult to manufacture many types of crystal forms at once using a single reaction vessel.

In addition, diamond is extremely hard and difficult to machine, and the particles could not be sintered by holding them at a high temperature, making them spherical, rod-like, needle-like, sheet-like, columnar, There was a further problem that it was difficult to obtain a different shape.

In the present invention, hydrogen and hydrocarbons generated from a carbon material are thermally excited by hot isostatic pressing of the carbon material in which hydrogen remains. It is characterized by depositing, generating and growing diamond material. In the present invention, it is not necessary to supply a source gas as in the conventional vapor phase growth method, and vapor phase growth is performed by hydrogen and hydrocarbons generated from a carbon material as a base material. That is, since hydrogen generation, etching of carbon material as a base material with hydrogen, hydrocarbon generation, diamond precipitation, and hydrogen generation occur repeatedly and continuously, the present invention is based on the carbon material itself as a raw material. It has the characteristic advantage that precipitation, generation and growth are efficiently performed at a high growth rate.

The present invention also provides a material characterized by containing diamond or the like as a production aid serving as a nucleus of growth and accelerating diamond growth by subsequent hot isostatic pressing. Specifically, the carbon material having hydrogen remaining accelerates the above-described diamond precipitation, generation and growth around a generation auxiliary agent serving as a nucleus during hot isostatic pressing. Production aids include diamond, tungsten, molybdenum, tantalum, copper, gold, platinum, silicon, nickel, cobalt, iridium, glassy carbon, graphite, silicon oxide, sapphire and other oxides, silicon carbide, tungsten carbide, titanium carbide Carbide such as boron nitride, nitride such as aluminum nitride, carbonate inorganic material such as magnesium carbonate, sulfate inorganic material such as calcium sulfate, etc. can be suitably used.

In the present invention, the temperature for pre-firing the carbon material is set to an appropriate condition in order to appropriately set the residual hydrogen amount before the hot isostatic pressing process of the carbon material. When the pre-calcination temperature is high, the amount of residual hydrogen is insufficient, so that hydrogen and hydrocarbons are not generated stably in order to precipitate and generate diamond in the subsequent hot isostatic pressing process. .

The present invention is also characterized in that a carbon material containing the above-mentioned production aid such as diamond also functions as a reaction vessel. In order to grow diamonds stably, it is necessary to create appropriate hydrogen, hydrocarbon concentration, and excited state at the reaction points where diamonds are generated, and it is necessary to stably maintain and support the growing diamonds while surrounding them. There is. In order to stably perform such a diamond precipitation and production process, a mixture of a carbon material and / or a precursor organic polymer material and a production aid is formed into a predetermined shape. Furthermore, when producing diamonds of a desired size and shape, the carbon material and a predetermined shape such as a plate, a sphere, a cylinder, and a vertical column with an appropriate generation aid held inside or on the surface Or the organic polymer material used as a precursor is shape | molded.

As the carbon material to function as a reaction vessel, a DLC film containing hydrogen by high-frequency plasma CVD, an amorphous carbon film, or the like can be used in addition to a polymer organic material in which hydrogen remains after firing.

When manufacturing thin-film diamond, the substrate-like formation aid or the substrate on which the production aid is placed and the carbon material are laminated, and if necessary, the entire surface is covered with the carbon material. It is characterized by hot isostatic pressing. In this case as well, since hot isostatic pressing with argon, nitrogen, etc. is performed, the concentration gradient of hydrogen and hydrocarbons is maintained around the substrate material and carbon material in an isotropic gas atmosphere. Generation and growth are promoted.

In the present invention, a space having a predetermined shape such as a columnar shape, a conical shape, a vertical column shape, a vertical cone shape, a plate shape, a spherical thin film shape, or the like is preliminarily installed on the inside or surface of the carbon material, and hot hydrostatic pressure is applied. Also provided is a material characterized by forming diamond material by depositing, generating and growing diamond in the installed space by pressure treatment.

According to the present invention, using a general-purpose hot isostatic pressing apparatus, granular, powdery and massive diamonds can be produced with high productivity even at a low pressure of about 0.2 GPa. Since the carbon material to be used is a raw material and a reaction vessel, a large number of treatments and diamond formations of various shapes, sizes, and crystal forms can be mixed and combined into a single hot isostatic pressing process. Can be implemented.
In the present invention, for example, a large-sized reaction vessel having an inner diameter of 800 mm and a height of 3500 mm can be manufactured, so that a large number of various types of products can be manufactured in a short period of time and at a low cost with a minimum necessary capital investment.

Furthermore, according to the present invention, it is possible to form a diamond thin film in a state in which a large number of substrates are laminated, so that it is possible to manufacture with extremely high productivity. For this reason, it is possible to put it into practical use for diamond thin films that have excellent characteristics but are difficult to put to practical use industrially, and ideal heat sinks, radiation, X-ray monitors, biosensors, chemical electrodes, power devices, and high-frequency devices. Promoted.

In addition, according to the present invention, when the carbon material is previously provided with a cylindrical shape, a conical shape, a vertical column shape, a vertical cone shape, a plate shape, a spherical shape, a thin film shape, etc., the column shape, the conical shape, It is possible to mold diamond materials such as vertical columns, vertical cones, plates, spheres, and thin films.

FIG. 1 is a drawing-substituting photograph showing an electron microscopic image of Example 12 (sample of Example 1). FIG. 2 is a drawing-substituting photograph showing an electron microscope image of Example 12 (sample of Example 2). FIG. 3 is a drawing-substituting photograph showing an electron microscope image of Example 12 (sample of Example 4). FIG. 4 shows the X-ray spectroscopic spectrum of Example 12 (sample of Example 4), which shows the presence of oxygen in the functional group terminated at the SP3 bond on the surface of diamond. FIG. 5 is a drawing-substituting photograph showing an electron microscope image of Example 12 (sample of Example 5). FIG. 6 is a drawing-substituting photograph showing an electron microscopic image of Example 12 (sample of Example 6). FIG. 7 is a drawing-substituting photograph showing an electron microscopic image of Example 12 (sample of Example 7). FIG. 8 is a drawing-substituting photograph showing an electron microscopic image of Example 12 (sample of Example 8). FIG. 9 is a drawing-substituting photograph showing an electron microscopic image of Example 12 (sample of Example 9). FIG. 10 is a drawing-substituting photograph showing an electron microscopic image of Example 12 (sample of Example 10). FIG. 11 is a drawing-substituting photograph showing an electron microscopic image of Example 12 (sample of Example 11). FIG. 12 shows an electron microscopic image of Example 13. FIG. 13 is an enlarged view of the electron microscope image of the dendritic diamond shown in FIG.

Organic polymer materials such as thermosetting resins and thermoplastic resins that carbonize after firing, and mixing aids as necessary, are mixed into thin plates, thick plates, discs, spheres, vertical columns, cylinders, cones, pyramids, etc. Mold into a predetermined shape. Any organic polymer material can be used as long as carbon becomes a residue after firing, but phenolic resin, furan resin, melamine resin, xylene resin, aniline resin, petroleum pitch. Coal pitch, PAN resin, epoxy resin, polyethylene, polystyrene, polypropylene, etc. can be suitably used. For the molding method, an appropriate method is selected according to the diamond material to be manufactured, such as compression-press molding using a mold, injection molding, casting, printing, spraying, rolling.

A molded body of organic polymer material containing diamond processed into a predetermined shape is carbonized and fired at a predetermined maximum temperature in an inert gas such as nitrogen at a predetermined temperature increase rate. The maximum temperature reached during carbonization and firing is determined by the hydrogen content remaining in the material after carbonization and firing. In the case of thermosetting resins such as phenol resins, hydrogen and hydrocarbons are generated from the CnHm functional group in the carbon skeleton in the temperature range of 800 ° C to 1500 ° C, causing carbonization and graphitization while causing material shrinkage. Go. In order to cause precipitation and growth of diamond in the subsequent hot isostatic pressing, it is necessary to generate appropriate hydrogen and hydrocarbons. decide.

The material after carbonization firing is inserted into a holding vessel such as a graphite crucible, and isotropic hot isostatic pressing with gas pressure is performed in an inert gas such as argon or nitrogen. Even at a relatively low pressure of about 0.2 GPa, for example, hydrogen is generated from a temperature range of 800 ° C. or higher, preferably 1000 ° C. or higher, and when heated to about 1800 ° C. to 2000 ° C., hydrogen generated from the carbon material Thermal excitation becomes active and diamond deposition and growth reactions are promoted on the surface of the diamond material. Since hydrogen generation, hydrocarbon generation, and diamond deposition from the carbon material occur repeatedly, diamond grows while consuming the surrounding carbon material.

The processing temperature for hot isostatic pressing may be in the temperature range where hydrogen is generated from the carbon material. However, since the generated hydrogen needs to be sufficiently thermally excited, for example, 800 ° C. or higher, preferably 1000 From the viewpoint of productivity, 1800 ° C. or higher, more preferably 2000 ° C. or higher, and 2100 ° C. or higher are more preferable. The upper limit of the treatment temperature is not particularly limited, but when a hot isostatic press is used, the upper limit is usually determined automatically from the performance of the apparatus. Such an upper limit is obvious to those skilled in the art and is usually about 2500 ° C., especially about 3000 ° C. for high performance values. A preferable processing temperature range can be appropriately selected from the above, and examples thereof include about 1800 ° C. to about 2500 ° C.
As the treatment pressure when performing the hot isostatic pressing, about 0.05 GPa or more, more preferably about 0.1 GPa or more, and more preferably about 0.19 GPa or more can be mentioned. The upper limit value of the processing pressure is not particularly limited. However, when a hot isostatic pressure apparatus is used, the upper limit value is usually determined from the performance of the apparatus. Such an upper limit is obvious to those skilled in the art and is usually about 0.2 GPa, especially about 0.3 GPa for high performance devices. A preferable processing pressure range can be appropriately selected from the above.
The processing pattern such as the processing pressure, the pressure increase rate, the simultaneous temperature increasing pressure increasing pattern, the pressure increasing preceding processing pattern, and the temperature increasing preceding pattern during the hot isostatic pressing process is appropriately selected according to the shape and crystal state of the diamond to be manufactured. Usually, from the viewpoint of reaction efficiency, the pressure increasing preceding pattern is preferable. As an example of the pattern, the processing pressure is sufficiently increased before the processing temperature reaches the maximum temperature at the time of carbonization baking (preliminary baking). As the value of the sufficiently increased processing pressure, for example, in the case of the processing conditions listed in the examples, about 0.15 GPa can be mentioned.

In the present invention, the amount of hydrogen contained in the carbon material is preferably in the range of about 0.01 wt% to about 6 wt% of the carbon material, more preferably in the range of about 0.05 wt% to about 6 wt%. More preferably, it is in the range of 0.2 wt% to 6 wt%.
Production aids include diamond, tungsten, molybdenum, tantalum, niobium, gallium, copper, gold, platinum, silicon, nickel, cobalt, iridium, glassy carbon, graphite, silicon oxide, oxides such as sapphire, silicon carbide, Carbides such as tungsten carbide and titanium carbide, nitrides such as boron nitride and aluminum nitride, inorganic carbonate materials such as magnesium carbonate, and inorganic sulfate materials such as calcium sulfate can be preferably used.

Various methods can be selected as a method of constructing the carbon material and / or the production aid before the hot isostatic pressing treatment.
It is also possible to use a carbon material containing hydrogen without using an organic polymer material.
Hydrogen is contained using various methods such as thermal CVD using hydrocarbon gas, plasma CVD, sputtering using carbon target material, reactive sputtering, ion-assisted sputtering, ion-assisted CVD, ion plating, etc. The same production can be suitably carried out by configuring the carbon material in the vicinity of the production assistant.

Unitika phenol formaldehyde resin (UA) powder was hot-pressed at a temperature of 170 ° C. and molded into a shape having an outer diameter of 50 mm and a thickness of 5 mm. The molded resin substrate was sandwiched between artificial graphite shelf plates, and carbonized and fired at a maximum temperature of 450 ° C. at a firing rate of 2 ° C. per hour in a nitrogen stream. When the residual hydrogen content of the carbonized material was measured by an inert gas melting thermal conductivity method (EMGA621 manufactured by Horiba), 6 wt% of hydrogen remained.

Unitika phenol formaldehyde resin (UA) powder was hot-pressed at a temperature of 170 ° C. and molded into a shape having an outer diameter of 50 mm and a thickness of 5 mm. The molded resin substrate was sandwiched between artificial graphite shelf plates and carbonized and fired at a maximum temperature of 1000 ° C. at a firing rate of 2 ° C. per hour in a nitrogen stream. When the amount of residual hydrogen in the carbonized material was measured by an inert gas melting thermal conductivity method (EMGA621 manufactured by Horiba), 0.2 wt% of hydrogen remained.

Unitika phenol formaldehyde resin (UA) powder was hot-pressed at a temperature of 170 ° C. and molded into a shape having an outer diameter of 50 mm and a thickness of 5 mm. The molded resin substrate was sandwiched between artificial graphite shelf plates and carbonized and fired in a nitrogen stream at a firing rate of 2 ° C. per hour up to 1000 ° C. and at a maximum firing temperature of 1800 ° C. at a firing rate of 5 ° C. per hour. When the amount of residual hydrogen in the material after carbonization firing was measured by an inert gas melting thermal conductivity method (EMGA621 manufactured by Horiba), 0.005 wt% of hydrogen remained.

Unitika phenolformaldehyde resin (UA) powder 99 wt% and diamond powder 1 wt% with a particle size of 3 microns were mixed and hot pressed at a temperature of 170 ° C. to form an outer diameter of 50 mm and a thickness of 5 mm. The molded resin substrate was sandwiched between artificial graphite shelf plates and carbonized and fired at a maximum temperature of 1000 ° C. at a firing rate of 2 ° C. per hour in a nitrogen stream.

Unitika phenolformaldehyde resin (UA) powder 99 wt% and diamond powder 1 wt% with a particle size of 3 microns were mixed and hot pressed at a temperature of 170 ° C. to form an outer diameter of 50 mm and a thickness of 5 mm. The molded resin substrate was sandwiched between artificial graphite shelf plates and carbonized and fired at a maximum temperature of 1000 ° C. at a firing rate of 5 ° C. per hour in a nitrogen stream. In order to increase the temperature rising rate during the carbonization firing, a large number of pores were introduced into the sample after the carbonization firing.

Unitica Phenolformaldehyde Resin (UA) powder 99wt% and aluminum nitride, silicon carbide, silicon, magnesium carbonate 1wt% mixture were hot-pressed at a temperature of 170 ° C, outer diameter 50mm, thickness Molded into a 5 mm shape. The molded resin substrate was sandwiched between artificial graphite shelf plates and carbonized and fired at a maximum temperature of 1000 ° C. at a firing rate of 3 ° C. per hour in a nitrogen stream.

A mixture of 99 wt% of phenolic formaldehyde resin (UA) powder manufactured by Unitika and 1 wt% of a mixture of niobium and gallium was hot-pressed at a temperature of 170 ° C. to form a shape having an outer diameter of 50 mm and a thickness of 5 mm.
The molded resin substrate was sandwiched between artificial graphite shelf plates and carbonized and fired at a maximum temperature of 1000 ° C. at a firing rate of 3 ° C. per hour in a nitrogen stream.

Unitika phenolformaldehyde resin (UA) powder 99wt%, molybdenum, magnesium carbonate,
A mixture of 1 wt% of an aluminum mixture was hot-pressed at a temperature of 170 ° C. to form a shape having an outer diameter of 50 mm and a thickness of 5 mm.
The molded resin substrate was sandwiched between artificial graphite shelf plates and carbonized and fired at a maximum temperature of 1000 ° C. at a firing rate of 3 ° C. per hour in a nitrogen stream.

Unitica phenolformaldehyde resin (UA) 99 wt% and copper / calcium sulfate 1 wt% mixture were hot-pressed at a temperature of 170 ° C. to form an outer diameter of 50 mm and a thickness of 5 mm. . The molded resin substrate was sandwiched between artificial graphite shelf plates and carbonized and fired at a maximum temperature of 1000 ° C. at a firing rate of 3 ° C. per hour in a nitrogen stream.

A carbon thin film with a thickness of 5 microns is formed on the surface of a single crystal silicon carbide wafer having an outer diameter of 50 mm and a plate thickness of 0.3 mm by using a plasma ion implantation film forming apparatus to form a laminate of silicon carbide and a carbon film. did. The film forming conditions were adjusted so that the amount of residual hydrogen in the carbon thin film was 3 wt%.

The both surfaces of the sample prepared in Example 2 were lapped and polished to finish a mirror surface with a surface roughness of Ra 5 angstroms. The outer diameters of the sample and the single crystal silicon carbide wafer were adjusted to 40 mm, and the flatness of each sample was adjusted.

The samples of Examples 1 to 11 were loaded into a graphite crucible, set in a reaction vessel of a hot isostatic press, and processed at a processing temperature of 2300 ° C. and a pressure of 0.19 GPa using argon gas. The time was maintained and hot isostatic pressing was performed. Table 1 summarizes the occurrence of diamond after the treatment.

 

Unitika phenolformaldehyde resin (UA) 99 wt% and diamond powder 1 wt% with a particle size of 30 microns were mixed and hot-pressed at a temperature of 170 ° C. to form an outer diameter of 50 mm and a thickness of 5 mm. The molded resin substrate was sandwiched between artificial graphite shelf plates and carbonized and fired at a maximum temperature of 800 ° C. at a firing rate of 2 ° C. per hour in a nitrogen stream.
The sample obtained above was loaded into a graphite crucible, set in a reaction vessel of a hot isostatic press, and treated with argon gas at a processing temperature of 2300 ° C. and a pressure of 0.19 GPa for 1 hour. It was held and subjected to hot isostatic pressing. After the treatment, dendritic diamond was formed (FIGS. 12 and 13).

ダ イ ヤ モ ン ド Diamond materials can be manufactured even at low pressures of about 0.2 GPa using a general-purpose hot isostatic pressing device, so the practical use of diamond materials with excellent characteristics will expand.

Claims (14)

1. A hydrogen-containing carbon material formed into a predetermined shape is prepared, and this is subjected to hot isostatic pressing with the pressure of the gas under a pressurized gas atmosphere, and the inside and / or the surface of the carbon material. A method for producing diamond, characterized in that diamond is produced.
2. The production method according to claim 1, wherein the carbon material containing hydrogen is obtained by firing an organic polymer material so as to contain residual hydrogen, diamond-like carbon (DLC), or amorphous carbon.
3. The method according to claim 1 or 2, wherein the amount of hydrogen contained in the carbon material is 0.01 wt% to 6 wt% of the carbon material.
4. The method according to claim 1 or 2, wherein the amount of hydrogen contained in the carbon material is 0.05 wt% to 6 wt% of the carbon material.
5. The method according to claim 1 or 2, wherein the amount of hydrogen contained in the carbon material is 0.2 wt% to 6 wt% of the carbon material.
6. The manufacturing method according to any one of claims 1 to 5, wherein the hot isostatic pressure treatment is performed under a temperature condition of 800 ° C to 3000 ° C.
7. The manufacturing method according to any one of claims 1 to 5, wherein the hot isostatic pressing process is performed under a temperature of 1800 ° C to 2500 ° C.
8. The manufacturing method according to any one of claims 1 to 7, wherein the hot isostatic pressing process is performed under a condition of the gas pressure of 0.01 GPa to 0.3 GPa.
9. The production method according to any one of claims 1 to 8, wherein the carbon material comprises a growth assistant.
10. The method according to any one of claims 1 to 8, wherein the carbon material is formed on the surface of a layer made of a growth aid or is in close contact therewith.
11. The growth aid is diamond, tungsten, molybdenum, tantalum, niobium, gallium, copper, gold, platinum, silicon, nickel, cobalt, iridium, glassy carbon, graphite, silicon oxide, sapphire oxide, silicon carbide, carbonized The method according to claim 9 or 10, wherein the production method is one or more selected from the group consisting of tungsten, titanium carbide, boron nitride, aluminum nitride, magnesium carbonate, and calcium sulfate.
12. The method according to claim 9 or 10, wherein the growth aid is diamond.
13. The manufacturing method according to claim 10, wherein the layer made of the growth assistant is a film-like single crystal silicon carbide.
14. 14. The carbon material according to any one of claims 1 to 13, wherein the carbon material has a space of a predetermined shape inside or on the surface, and diamond is generated in the space by hot isostatic pressing. Manufacturing method.

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