National Chung Shan Institute of Science and Technology

Taisic Materials Corp.

Dai-Liang Ma

Bang-Ying Yu

Cheng-Jung Ko

Bo-Cheng Lin

Chih-Wei Kuo

Jun-Bin Huang

Hsueh-I Chen

Tsao-Chun Peng

Ying-Cong Zhao

Chia-Hung Tai

Ta-Ching Li

Shu-Yu Yeh

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.

Semi-insulating single-crystal silicon carbide bulk material and powder

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 μm and 350 μm; 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 silicon carbide powder has a third silicon-vacancy concentration and a second particle diameter, the third silicon-vacancy concentration is greater than 5E11 cm{circumflex over ( )}−3, and the second particle diameter is between 1 μm and 50 μm.

Manufacturing method of semi-insulating single-crystal silicon carbide powder

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 (&#x2003;)}-3.

High-purity semi-insulating single-crystal silicon carbide wafer and crystal

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.

Method for the formation of tantalum carbides on graphite substrate

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.

Preparation apparatus for silicon carbide crystals comprising a circular cylinder, a doping tablet, and a plate

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.

Method for fabricating ultra-thin graphite film on silicon carbide substrate from siloxane-coupling-group-containing polyamic acid solution

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.

Device for measuring distribution of thermal field in crucible

A device for growing large-sized monocrystalline crystals, including a crucible adapted to grow crystals from a material source and with a seed crystal and including therein a seed crystal region, a growth chamber, and a material source region; a thermally insulating material disposed outside the crucible and below a heat dissipation component; and a plurality of heating components disposed outside the thermally insulating material to provide heat sources, wherein the heat dissipation component is of a heat dissipation inner diameter and a heat dissipation height which exceeds a thickness of the thermally insulating material.

Device for growing monocrystalline crystal

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.

Method of producing heterophase graphite

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.

Growing community of inventors

Taoyuan, Taiwan

Dai-Liang Ma