Abstract: Disclosed is a device for preparing a silicon carbide crystal including a crucible and a crystal expansion guide assembly. The crucible includes a crucible body and a crucible cover fixing a seed and covering the crucible body. The crystal expansion guide assembly includes a frame member and a tubular core member. The frame member is fixed to the crucible body, located between the crucible cover and a raw material accommodated in the crucible body, and provided with a through hole with a diameter greater than a diameter of a growth surface of the seed. The tubular core member is mechanically connected to an inner wall of the through hole. During a crystal growth process, the tubular core member falls off due to contact with a growth front of a crystal. The frame member does not react with the crystal. Thus, a large-sized crystal ingot with high quality can be obtained.

Abstract: Disclosed is a silicon carbide crystal growth system including a crucible, a heating device and a seed holder. The crucible includes a crucible body and a crucible cover covering the crucible body. The heating device includes a quartz tube and an induction coil spirally wound on an outer wall of the quartz tube. The crucible is disposed in the quartz tube. The crucible is disposed coaxially with the quartz tube. The seed holder is disposed on the crucible cover and includes a seed holding surface for holding an off-axis seed and is perpendicular to a central axis of the crucible, and an angle between a normal direction of the induction coil and a growth direction of the off-axis seed is between 0 degrees and 10 degrees, so that a silicon carbide crystal grows from the off-axis seed along isotherms provided by the induction coil, thereby obtaining a silicon carbide boule.

Abstract: Disclosed is a method for purifying a graphite material, which includes the following steps of: after placing the graphite material in a graphite crucible, placing the graphite crucible into a heating furnace; after vacuuming the heating furnace, filling the heating furnace with a protective atmosphere, and controlling a pressure in the heating furnace to be less than 5 Torr; and heating the graphite crucible, by a heater disposed in the heating furnace, to control a temperature of the graphite crucible to be at least higher than melting point temperatures of some metal impurities in the graphite material for a preset time period, so that the some metal impurities in the graphite material are volatilized or carbonized, and the graphite crucible is purified. Therefore, while the graphite material is purified under a condition with high vacuum, high temperature and low pressure, the graphite crucible is also purified.

Abstract: The present disclosure provides a manufacturing method of semi-insulating single-crystal silicon carbide powder comprising: providing a semi-insulating single-crystal silicon carbide bulk, wherein the semi-insulating single-crystal silicon carbide bulk has a first silicon-vacancy concentration, and the first silicon-vacancy concentration is greater than 5E11 cm{circumflex over (?)}?3; refining the semi-insulating single-crystal silicon carbide bulk to obtain a semi-insulating single-crystal silicon carbide coarse particle, wherein the semi-insulating single-crystal silicon carbide coarse particle has a second silicon-vacancy concentration and a first particle diameter, the second silicon-vacancy concentration is greater than 5E11 cm{circumflex over (?)}?3, and the first particle diameter is between 50 ?m and 350 ?m; self-impacting the semi-insulating single-crystal silicon carbide coarse particle to obtain a semi-insulating single-crystal silicon carbide powder, wherein the semi-insulating single-crystal sili

Abstract: The present disclosure provides high-purity semi-insulating single-crystal silicon carbide wafer and crystal which include one polytype single crystal. The semi-insulating single-crystal silicon carbide wafer has silicon vacancy inside, wherein the silicon-vacancy concentration is greater than 5E11 cm{circumflex over (?)}-3.

Abstract: The present disclosure provides a manufacturing method of semi-insulating single-crystal silicon carbide powder comprising: providing a semi-insulating single-crystal silicon carbide bulk, wherein the semi-insulating single-crystal silicon carbide bulk has a first silicon-vacancy concentration, and the first silicon-vacancy concentration is greater than 5E11 cm{circumflex over (?)}?3; refining the semi-insulating single-crystal silicon carbide bulk to obtain a semi-insulating single-crystal silicon carbide coarse particle, wherein the semi-insulating single-crystal silicon carbide coarse particle has a second silicon-vacancy concentration and a first particle diameter, the second silicon-vacancy concentration is greater than 5E11 cm{circumflex over (?)}?3, and the first particle diameter is between 50 ?m and 350 ?m; self-impacting the semi-insulating single-crystal silicon carbide coarse particle to obtain a semi-insulating single-crystal silicon carbide powder, wherein the semi-insulating single-crystal sili

Abstract: The present disclosure provides high-purity semi-insulating single-crystal silicon carbide wafer and crystal which include one polytype single crystal. The semi-insulating single-crystal silicon carbide wafer has silicon vacancy inside, wherein the silicon-vacancy concentration is greater than 5E11 cm{circumflex over (?)}-3.

Abstract: The present disclosure provides semi-insulating single-crystal silicon carbide bulk material and powder which include one polytype single crystal. The semi-insulating single-crystal silicon carbide bulk material has silicon vacancy inside, wherein the silicon-vacancy concentration is greater than 5E11 cm{circumflex over (?)}?3.

Abstract: A method for the formation of tantalum carbides on a graphite substrate includes the steps of: (a) adding an organic tantalum compound, a chelating agent, a pre-polymer to an organic solvent to form a tantalum polymeric solution; (b) subjecting a graphite substrate with the tantalum polymeric solution to a curing process to form a polymeric tantalum film on the graphite substrate; and (c) subjecting the polymeric tantalum film on the graphite substrate in an oven to a pyrolytic reaction in the presence of a protective gas to obtain a protective tantalum carbide on the graphite substrate.

Abstract: A preparation apparatus for uniform silicon carbide crystals comprises a circular cylinder, a doping tablet, and a plate to stabilize and control the supply of dopants. The accessory does not participate in the reaction in the growth chamber but maintains its efficacy during growth. Finally, a single semi-insulating silicon carbide crystal with uniform electrical characteristics can be obtained.

Abstract: A method for fabricating an ultra-thin graphite film on a silicon carbide substrate includes the steps of: (A) providing a polyamic acid solution and a siloxane-containing coupling agent for polymerizing under an inert gas atmosphere to form a siloxane-coupling-group-containing polyamic acid solution; (B) performing a curing process after applying the siloxane-coupling-group-containing polyamic acid solution to a silicon carbide substrate; (C) placing the silicon carbide substrate in a graphite crucible before placing the graphite crucible in a reaction furnace to perform a carbonization process under an inert gas atmosphere; (D) subjecting the silicon carbide substrate to a graphitization process to obtain a graphite film, thereby make it possible to fabricate an ultra-thin graphite film of high-quality on the surface of silicon carbide in a lower graphitization temperature range.

Abstract: A preparation apparatus for uniform silicon carbide crystals comprises a circular cylinder, a doping tablet, and a plate to stabilize and control the supply of dopants. The accessory does not participate in the reaction in the growth chamber but maintains its efficacy during growth. Finally, a single semi-insulating silicon carbide crystal with uniform electrical characteristics can be obtained.

Abstract: A method for the formation of tantalum carbides on a graphite substrate includes the steps of: (a) adding an organic tantalum compound, a chelating agent, a pre-polymer to an organic solvent to form a tantalum polymeric solution; (b) subjecting a graphite substrate with the tantalum polymeric solution to a curing process to form a polymeric tantalum film on the graphite substrate; and (c) subjecting the polymeric tantalum film on the graphite substrate in an oven to a pyrolytic reaction in the presence of a protective gas to obtain a protective tantalum carbide on the graphite substrate.

Abstract: A method for fabricating an ultra-thin graphite film on a silicon carbide substrate includes the steps of: (A) providing a polyamic acid solution and a siloxane-containing coupling agent for polymerizing under an inert gas atmosphere to form a siloxane-coupling-group-containing polyamic acid solution; (B) performing a curing process after applying the siloxane-coupling-group-containing polyamic acid solution to a silicon carbide substrate; (C) placing the silicon carbide substrate in a graphite crucible before placing the graphite crucible in a reaction furnace to perform a carbonization process under an inert gas atmosphere; (D) subjecting the silicon carbide substrate to a graphitization process to obtain a graphite film, thereby make it possible to fabricate an ultra-thin graphite film of high-quality on the surface of silicon carbide in a lower graphitization temperature range.

Abstract: A device for measuring distribution of thermal field in a crucible comprises a crucible comprising an upper lid, a body, a growth chamber and a material source zone; a thermally insulating material disposed outside the crucible; a movable heating component for heating the crucible; a plurality of thermocouples enclosed by insulating, high temperature resistant material and disposed in the crucible after being inserted into a plurality of holes on the upper lid to measure distribution of thermal field in the crucible. The thermocouples enclosed by insulating, high temperature resistant material are effective in measuring and adjusting temperature distribution in the crucible to achieve optimal temperature distribution for crystal growth in the crucible.

Abstract: A device for growing a carbide of specific shape includes (A) a crucible; (B) a raw material source zone where a SiC raw material precursor is accessible; (C) a deposition zone where SiC is grown; (D) a gas temperature gradient control zone characterized by a temperature gradient; (E) a current deposition carrier disposed within the deposition zone and characterized by at least one repetition of a succession of one or at least two specific shapes of the current deposition carrier; and (F) a heating component for heating the SiC raw material precursor to turn it into gas molecules, so as to effectuate its deposition on the current deposition carrier.

Abstract: A device for measuring distribution of thermal field in a crucible comprises a crucible comprising an upper lid, a body, a growth chamber and a material source zone; a thermally insulating material disposed outside the crucible; a movable heating component for heating the crucible; a plurality of thermocouples enclosed by insulating, high temperature resistant material and disposed in the crucible after being inserted into a plurality of holes on the upper lid to measure distribution of thermal field in the crucible. The thermocouples enclosed by insulating, high temperature resistant material are effective in measuring and adjusting temperature distribution in the crucible to achieve optimal temperature distribution for crystal growth in the crucible.

Abstract: A method of producing a heterophase graphite, including the steps of (A) providing a silicon carbide single-crystal substrate; (B) placing the silicon carbide single-crystal substrate in a graphite crucible and then in a reactor to undergo an air extraction process; and (C) performing a desilicification reaction on the silicon carbide single-crystal substrate in an inert gas atmosphere to obtain 2H graphite and 3R graphite, so as to directly produce lumpy (sheetlike, crushed, particulate, and powderlike) 2H graphite and 3R graphite, and preclude secondary contamination of raw materials which might otherwise occur because of a crushing step, an oxidation step, and an acid rinsing step.

Abstract: A method of producing a heterophase graphite, including the steps of (A) providing a silicon carbide single-crystal substrate;(B) placing the silicon carbide single-crystal substrate in a graphite crucible and then in a reactor to undergo an air extraction process; and (C) performing a desilicification reaction on the silicon carbide single-crystal substrate in an inert gas atmosphere to obtain 2H graphite and 3R graphite, so as to directly produce lumpy (sheetlike, crushed, particulate, and powderlike) 2H graphite and 3R graphite, and preclude secondary contamination of raw materials which might otherwise occur because of a crushing step, an oxidation step, and an acid rinsing step.

Abstract: A method of producing a carbide raw material includes the steps of (A) providing a porous carbon material and a high-purity silicon raw material or a metal raw material and applying the porous carbon material and the high-purity silicon raw material or a metal raw material alternately to form a layer structure; (B) putting the layer structure in a synthesis furnace to undergo a gas evacuation process; and (C) producing a carbide raw material with a synthesis reaction which the layer structure undergoes in an inert gas atmosphere, wherein the carbide raw material is a carbide powder of a particle diameter of less than 300 ?m, thereby preventing secondary raw material contamination otherwise arising from comminution, oxidation and acid rinsing.