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: 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: 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.

Abstract: A method of making a photonic crystal includes step 1 providing a seed, followed by etching a surface of the seed to form thereon submicron voids; step 2 providing a graphite disk, followed by coating a side of the graphite disk with a graphite adhesive whereby the void-formed surface of the seed is attached to the graphite disk to form a seed holder; step 3 placing the seed holder above a growth chamber, followed by placing a raw material below the growth chamber; step 4 forming a thermal field in the growth chamber with a heating device to sublime the raw material; and step 5 controlling temperature, thermal field, atmosphere and pressure in the growth chamber to allow the gaseous raw material to be conveyed and deposited on the seed, thereby forming a photonic crystal.

Abstract: A method of making a photonic crystal includes step 1 providing a seed, followed by etching a surface of the seed to form thereon submicron voids; step 2 providing a graphite disk, followed by coating a side of the graphite disk with a graphite adhesive whereby the void-formed surface of the seed is attached to the graphite disk to form a seed holder; step 3 placing the seed holder above a growth chamber, followed by placing a raw material below the growth chamber; step 4 forming a thermal field in the growth chamber with a heating device to sublime the raw material; and step 5 controlling temperature, thermal field, atmosphere and pressure in the growth chamber to allow the gaseous raw material to be conveyed and deposited on the seed, thereby forming a photonic crystal.

Abstract: A fabricating method for growing a single crystal of a multi-type compound comprises steps of: (a) providing a seed crystal at a deposition region; (b) providing a powder material at a high purity source region; and (c) undertaking a vacuum process, a heating process, a growing process, a cooling process to prepare the singe crystal, wherein a heating source is used to move to control a temperature gradient within a gas temperature control region to form a temperature gradient motion so that the temperature gradient presents a variation. By reducing the possibility of other deficiencies being continuously induced in the following crystal growth process owing to the local slime occurring at the rear side of the seed crystal from the void deficiencies at the rear side of the original seed crystal may be excluded, but also the possibility of other multi-type bodies being induced by the above vacancies.

Abstract: A method of producing a high-purity carbide mold includes the steps of (A) providing a template; (B) putting the template at a deposition region in a growth chamber; (C) putting a carbide raw material in the growth chamber; (D) providing a heating field; (E) introducing a gas; (F) depositing the carbide raw material; and (G) removing the template. The method is able to produce a mold from a high-purity carbide with a purity of 93% or above and therefore is effective in solving known problems with carbide molds, that is, low hardness and low purity.