KR200200524Y1 - Carbon nitride thin film, bulk formation equipment - Google Patents

Abstract

In the seed carbon nitride thin film forming apparatus according to the present invention, the laser beam 2 generated from the laser 1 is condensed with the lens 3, and the fixed high purity positioned in the vacuum chamber 5 with the driving reflector 4. When the graphite target 6 is irradiated, the laser plume 7 generated on the surface thereof and the high voltage discharge plasma 9 generated between the graphite cathode 6 and the anode 8 are mixed so as to be mixed. When the carbon nitride thin film 11 is formed on the substrate 10 on the graphite anode 8 without heating the substrate 10 by using a separate substrate heater due to the high temperature at the center of the generated plasma 9, the plasma zone The process of placing the reactor 12 enclosed by the zone and supplying a constant nitrogen gas to the guide tube 13 into the reactor 12 located inside the vacuum chamber 5 allows a large amount of atomic nitrogen to be transferred to the substrate 10. Reacts efficiently with carbon in the Α to form a carbon nitride thin film 11, sandwiching the seed thin film 11 in a specially formed high temperature high pressure furnace in a sandwich shape, and synthesizing by a chemical method between the laminated thin films 11 -C ₃ N _4.2 Filled with powder (14) and, upon reaching a certain high temperature, pressurized to form carbon nitride bulk, supplying nitrogen gas to the lamination wrapped with Ta or Mo (15) to minimize the loss of nitrogen content. It further comprises a device for charging through the tube (16).

Description

Carbon nitride thin film, bulk formation equipment

The present invention relates to an apparatus for producing carbon nitride including high quality carbon crystal thin film formation for seed crystal and high quality bulk carbon nitride. In order to form a carbon nitride thin film for seed crystal, which has not been conventionally considered, a carbon nitride thin film is formed by a lasma mixing method that specifically combines a laser ablation method and a high voltage discharge plasma CVD method. -C ₃ N ₄ ) bulk forming apparatus, which will be described in more detail. In the present invention, the above two methods complementarily specially combine to increase plasma density and thin film deposition rate efficiency. In order to form carbon nitride for seed crystals on a substrate in a short time, the plasma zone is surrounded by a high temperature heat-treated glass reactor, and nitrogen gas is supplied into the reactor through a guide tube during the deposition process, thereby providing a large amount of atomic nitrogen on the substrate. React with carbon to form a thin film of carbon nitride The method may further include supplying nitrogen gas to the center of the plasma, that is, near the substrate on which the seed carbon nitride thin film is formed, so as to increase the generation efficiency of atomic nitrogen. When used as a crystal to form a high quality carbon nitride (β-C ₃ N ₄ ) bulk under high temperature and high pressure conditions, the nitrogen-encapsulated layered layer may be nitrogen-laminated in order to allow the atomic nitrogen to fully function as in thin film formation. It relates to a carbon nitride bulk forming apparatus characterized by adding a process of filling and supplying gas to a constant pressure.

In the conventional carbon nitride synthesis process under high temperature and high pressure conditions, as shown in FIG. 2, a sample is formed without a carbon nitride thin film for seed crystal and charged into the high temperature and high pressure generating device, about 55 to 75 kbar. Carbon nitride (β-C ₃ N ₄ ) particles are produced by heating to a high temperature of about 500 to 1400 C while maintaining a pressure higher than the melting point of α-C ₃ N _4.2 . On the other hand, the resulting carbon nitride particles proceed toward α-C ₃ N _4.2 powder and become larger in size. However, when the carbon nitride thin film for seed crystal is not present, the probability of obtaining a carbon nitride crystal as described above is extremely low, which is 5% or less, and even if a carbon nitride crystal is obtained, its growth rate is very slow. The problem is that carbon nitride of a satisfactory size cannot be obtained.

The present invention was devised to improve the technical problems present in the synthesis of nitrogen carbide under high temperature and high pressure conditions by the above-described conventional method, and as shown in FIG. Using a carbon nitride thin film for seed crystal, the growth of carbon nitride crystal starts from nano-sized seed carbon nitride particles in the thin film and proceeds to α-C ₃ N _4.2 powder, and the size is satisfactory. It is devised to provide an apparatus for producing carbon nitride (β-C ₃ N ₄ ) that can grow up to 5 mm or more to overcome the above-mentioned limitations of the formation of carbon nitride and to increase the size of high quality carbon nitride powder. The purpose is to.

1 is a schematic view of a seed carbon nitride film formation process by the Lasma mixing method

Figure 2 is a cross-sectional structural diagram of carbon nitride bulk synthesis process by a conventional method

Figure 3 is a laminated arrangement cross-sectional structural view of the seed carbon nitride thin film (β-C ₃ N ₄ ) and α-C ₃ N _4.2 for forming a bulk carbon nitride of the present invention

* Explanation of symbols for main parts of the drawings

1: laser 2: laser beam

3: condenser lens 4: driven reflector

5: vacuum chamber 6: graphite target (cathode)

7: laser plum 8: anode (substrate holder)

9: plasma zone 10: substrate

11: seed carbon nitride thin film 12: reactor

13: nitrogen guide tube 14: α-C ₃ N _4.2 powder

15: Ta or Mo capsule 16: Tube for nitrogen supply

17: graphite heater 18: insulation

19: thermocouple

In order to achieve the object of the above invention, the present invention is the domestic patent application Nos. 10-2000-7403, 10-2000-7404, 10-2000-7405 and 10, filed by the applicant of the present invention Optical apparatus for thin film deposition by laser ablation method, diamond thin film and bulk formation method by laser ablation method and high voltage discharge plasma CVD method, laser ablation method, high voltage discharge plasma Thin film formation method by CVD method, mixing method of two methods, diamond film production method by laser ablation method and high voltage discharge plasma CVD method, and diamond bulk formation method under high temperature and high pressure conditions. The carbonaceous thin film for seed crystal, which will be used in the synthesis of bulk carbon nitride under high temperature and high pressure conditions, is formed by the lasma mixing method under Thereby. As shown in FIG. 1, a high voltage is applied between two pure (99.999%) graphite electrodes 6 and 8 spaced at regular intervals by a high voltage supply device to generate a discharge plasma 9 inside the reactor 12. Nitrogen gas in the surroundings is made into an excited atomic nitrogen and mixed with a large number of carbon atoms emitted from the cathode 6, and at the same time, the laser beam from the laser source is irradiated onto the graphite target 6 to provide a substrate 10 inside the plasma. A laser ablation method for protruding carbon particles with high kinetic energy to mix with atomic nitrogen in the plasma and depositing the mixed particles on a substrate located in the center of the plasma to form the carbon nitride thin film 11; Seed carbon nitride (β-C ₃₎ by specially combined rasma mixing method, so that the advantages and disadvantages of high voltage discharge plasma CVD are complementary N ₄ ) In the thin film formation method, the plasma zone 9 is surrounded by a high temperature heat-treated glass reactor 12 in order to increase the plasma density during the deposition process to improve deposition efficiency and speed. In this case, in order to efficiently react with carbon to deposit on the substrate, and to increase the generation efficiency of atomic nitrogen, nitrogen gas may be supplied to the center of the plasma where the carbon nitride thin film is formed, that is, close to the substrate. In order to use the guide tube 13 and to apply the laser beam 2 to the fixed target to have the same effect as the target 6 is rotating, the driven reflector 4 is used. A carbon nitride (β-C ₃ N ₄ ) thin film for seed crystals is formed.

When synthesizing bulk carbon nitride (β-C ₃ N ₄ ), which is the final object of the present invention, using the seed crystal carbon nitride thin film prepared by the above method, α-C ₃ prepared by the chemical method as shown in FIG. The seed carbon nitride thin films 11 deposited and deposited on the substrate 10 by a lattice method between N _4.2 powders 14 are alternately stacked and then surrounded by Ta or Mo capsules 15, which are high-temperature graphite. Charged in a high-pressure container with a built-in heater (17) and heated to a high temperature (500 ~ 1400 C) while applying a high pressure (50 ~ 75 kbar) seed carbon thin film (11) and α-C ₃ N _4.2 powder (14) The process reaction with and dissolves faster than the rest, resulting in the growth of crystals from the nano-sized seed carbon nitride. Nitrogen supply tube which is a special device to supply and supply nitrogen gas to the lamination layer surrounded by Ta or Mo capsule 15 to a certain pressure in order to minimize the loss of nitrogen during the formation of carbon nitride during the process It is a method of forming a high quality carbon nitride (β-C ₃ N ₄ ) bulk characterized by using 16).

Hereinafter, the present invention will be described with reference to the drawings.

Figure 1 is a schematic view of the seed carbon nitride thin film formation process by the Lasma mixing method, Figure 2 is a cross-sectional structural diagram of carbon nitride bulk synthesis process according to the conventional method and Figure 3 is a seed for forming the carbon nitride bulk of the present invention A cross-sectional structure diagram of a laminated arrangement of a carbon nitride thin film (β-C ₃ N ₄ ) and α-C ₃ N _4.2 is shown. A laser (1), a laser beam (2), a condenser lens (3), and a driving reflector (4) ), Vacuum chamber (5), graphite target (cathode) (6), laser plum (7), anode (substrate holder) (8), plasma zone (9), substrate (10), carbon nitride Thin film 11, reactor 12, nitrogen guide tube 13, α-C ₃ N _4.2 powder 14, Ta or Mo capsule 15, nitrogen supply tube 16, graphite heater (17), heat insulating material 18, and a thermocouple 19 are shown.

The present invention provides a substrate (10) formed in the inner center of the vacuum chamber (5), an anode (substrate holder) (8) formed under the substrate (10), and supplying nitrogen gas provided under the anode (8) A nitrogen guide tube 13, a laser plume 7 formed on the substrate 10 to form a thin film, and the laser plume 7 are formed and irradiated by a laser beam 2 A support for supporting the graphite target (cathode) 6 and the graphite target (cathode) 6, and a place for forming a thin film between the graphite target (cathode) 6 and the substrate 10 A plasma zone 9, a reactor 12 surrounding the plasma zone 9, a drive reflector 4 for reflecting the focused laser 1 to irradiate the target surface, and formed on one side opposite thereto It consists of a vacuum pump,

As shown in FIG. 3, the seed carbon nitride thin film 11 deposited on the substrate 10 by the lasma method and the inside of the seed carbon nitride thin film 11 are formed in the heat insulating material 18. And a first α-C ₃ N _4.2 powder 14 layer formed on the first substrate 10 and two second substrates 10 formed on the α-C ₃ N _4.2 powder 14 layer. ) and, wherein the first formed on the second substrate (10) 2 α-C ₃ N _4.2 powder (14) layer, wherein the second α-C ₃ N third substrate (10, _4.2 powder (14) layer formed on the upper The stacks alternately arranged in) are surrounded by Ta or Mo capsules 15, and a thermocouple 19 and a high temperature graphite heater 17 are built in, and nitrogen atoms are efficiently formed as in a thin film formation during diamond formation. In order to exert its function, it is composed of a nitrogen supply tube 16 so that nitrogen gas can be filled and supplied to a predetermined pressure in a lamination layer surrounded by Ta or Mo capsules 15. It is a device.

As a result, crystal growth occurs from the seed carbon nitride, which is nano-sized, and the growth proceeds toward the α-C ₃ N _4.2 powder (14) layer, and after a predetermined time, the crystals form carbon nitride bulk having a size (more than 5 mm). .

The method of operation is a target (Si or Ni) to form a thin film with alcohol or acetone. Etc.), the surface of the surface is cleaned with an ultrasonic cleaner for about 30 minutes, held in an object holder in the vacuum chamber, and pumped so that the inside of the chamber is a constant vacuum with a vacuum pump, and then Ar gas is injected into the chamber to a predetermined pressure. Applying a relatively low voltage between the two electrodes so that the plasma is formed only on the surface of the object, plasma cleaning the object surface (no separate object heating process is required), and then pumping the inside of the chamber with a constant vacuum with a vacuum pump. , Inject nitrogen gas into the chamber to a certain pressure,

As shown in FIG. 1, the laser beam generated from the laser source is irradiated to the fixed target 6 located in the vacuum chamber through the driving reflector optics, and the driving reflector 4 is rotated or linearly moved to laser the laser beam. At the same time, the spot rule of the light is circular (elliptical) or straight (cross) on the target 6 to protrude carbon particles having high kinetic energy from the surface of the target 6 toward the substrate 10 from inside the plasma. A high voltage supply device is applied between two pure (99.999%) graphite electrodes 6 and 8 spaced at regular intervals so that a discharge plasma is generated throughout the reactor, so that nitrogen gas is supplied to a nitrogen gas supply tube to the plasma reactor 13. Nitrogen gas supplied up to the inside is made into atomic nitrogen in an excited state and mixed with a large number of carbon atoms emitted from the cathode (6). After depositing on the substrate located in the negative portion to form the carbon nitride thin film 11,

In order to increase the plasma density during the deposition process described above, the plasma zone 9 is enclosed by the high temperature heat-treated glass reactor 12 to improve the deposition efficiency and speed. In this case, in order to induce the nitrogen atoms to react with carbon to deposit on the substrate and to increase the generation efficiency of atomic nitrogen, nitrogen gas may be supplied to the center of the plasma where the carbon nitride thin film is formed, that is, near the substrate. Using a special guide tube 13 and a driven reflector 4 to produce the same effect as the target 6 is rotating when irradiating the laser beam 2 onto a fixed target. To form a carbon nitride (β-C ₃ N ₄ ) thin film for seed crystals,

Alternatingly arranging the seed carbon nitride thin films 11 deposited and manufactured on the substrate 10 by the lasma method between the α-C ₃ N _4.2 powders 14 produced by the chemical method as shown in FIG. It is then encased in a Ta or Mo capsule (15), and charged into a high-pressure vessel containing a high temperature graphite heater (17) and heated to a high temperature (500 ~ 1400 degrees Celsius) while applying a high pressure (50 ~ 75 kbar) seeds Due to the process reaction between the carbon nitride thin film 11 and the α-C ₃ N _4.2 powder 14, it dissolves faster than the other portions, and thus growth occurs from the seed carbon nitride crystal having a nano size. Nitrogen supply tube which is a special device to supply and supply nitrogen gas to the lamination layer surrounded by Ta or Mo capsule 15 to a certain pressure in order to minimize the loss of nitrogen during the formation of carbon nitride during the process 16) was used to form a high quality carbon nitride (β-C ₃ N ₄ ) bulk. (The thin film prepared by the lasma mixture method of the 1, 2, 3 process as a seed crystal using a high temperature and high pressure conditions Production of Nitrogen Carbide Bulk Under)

Diamond may be formed in the above, and other precious metals may be formed as needed or according to the user's preference.

In the present invention, in order to manufacture the carbon nitride thin film for the seed crystal, in order to compensate for the disadvantages of the laser ablation method only and to increase the efficiency of the plasma CVD method under nitrogen atmosphere, the above two types of formation methods are specifically combined. The plasma zone in the reactor located in the center of the vacuum chamber is surrounded by a glass reactor manufactured by high temperature heat treatment, and the density of the plasma zone is increased to improve the excitation efficiency of the nitrogen gas and the deposition rate of the thin film. When the seed carbon nitride thin film is formed on the substrate placed on the graphite anode without heating with a separate substrate heater, the seed carbon nitride thin film having better quality is produced in a shorter time than the conventional method. When nitrogen is supplied together with a certain percentage of hydrogen gas when the nitrogen is supplied through the guide tube to the inside of the reactor, the graphite phase (C = N: sp, C) is caused by the atomic hydrogen changed in the high density plasma. The carbon atoms that will form ≡N: sp ² ) are desorbed from the substrate by reacting with atomic hydrogen, so that only a pure diamond phase (CN: sp ³ ) is present on the substrate.

In the present invention, by using the high quality carbon nitride thin film manufactured by the above-mentioned Raisma mixing method as a seed crystal, by synthesizing the bulk under high temperature and high pressure conditions, a large amount of high quality carbon nitride bulk having a large size and density of carbon nitride powder The advantage is that it can be manufactured in a short time. When nitrogen gas is supplied in a certain ratio with hydrogen gas through a gas supply tube, which is a special device for filling and supplying a lamination layer surrounded by Ta or Mo capsules, it is seeded by atomic hydrogen changed in a furnace of high temperature and high pressure. As in thin film deposition, the carbon atoms to form the graphite phase (sp, sp ² ) are desorbed from the bulk carbon by reacting with atomic hydrogen, so that only a pure diamond phase (sp ³ ) is present.

Claims (1)

In the apparatus for producing carbon nitride using particles of a synthetic carbon nitride thin film manufactured by laser ablation method, plasma CVD method, or a lasma mixture method combining both methods, a carbon nitride is formed in the inner center of the vacuum chamber 5. Nitrogen hydrogen gas guide tube 13 for mixing and supplying a substrate 10, an anode (substrate holder) 8 formed under the substrate 10, and nitrogen and hydrogen provided at the lower portion of the anode 8 at a constant ratio. ), A laser plume (7) formed on the substrate (10) to form a thin film, and a graphite target (cathode) (6) which forms the laser plume (7) and is irradiated by a laser beam (2). And a support for supporting the graphite target (cathode) 6, a plasma zone 9 which is a place for forming a thin film between the graphite target (cathode) 6 and the substrate 10, and the plasma A reactor 12 surrounding the zone 9, The drive reflector 4 reflecting the pre-collected laser 1, the vacuum pump formed on the opposite side thereof, the seed carbon nitride thin film 11 deposited on the substrate 10, and the seed carbon nitride thin film ( 11) a first substrate 10 in the heat insulating material 18, a first α-C ₃ N _4.2 powder (14) layer formed on the first substrate 10, and the α-C ₃ N _4.2 Two second substrates 10 formed on top of the powder 14 layer, a second α-C ₃ N _4.2 powder 14 layer formed on the second substrate 10, and the second α-C ₃ N _4.2 A stack of alternating layers stacked on a third substrate 10 formed on top of the powder 14 layer is surrounded by Ta or Mo capsules 15, and a thermocouple 19 and a high temperature graphite heater 17 are built in. In order to allow nitrogen atoms to function as efficiently as during thin film formation during the diamond formation process, nitrogen gas is charged up to a constant pressure in the lamination layer enclosed with Ta or Mo capsules (15). Apparatus for manufacturing a carbon nitride, characterized by configured to include a tube 16 for the supply of nitrogen to be in a hurry.