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A kind of preparation method of high-purity silicon carbide raw material

A technology of high-purity silicon carbide and silicon carbide materials, applied in chemical instruments and methods, carbon compounds, inorganic chemistry, etc., can solve problems such as micropipes, high silicon carbide, and low purity

Active Publication Date: 2015-08-19
安徽微芯长江半导体材料有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0004] However, just like the production of silicon wafers requires high-purity silicon materials, the production of silicon carbide wafers also requires high-purity silicon carbide raw materials. Due to the inherent defects of the current traditional method, the content of various impurities in the produced silicon carbide is relatively high. The purity is relatively low, and it is very easy to produce defects such as polycrystals, micropipes, dislocations, and wrapping when growing silicon carbide crystals as raw materials, making it difficult to form high-quality silicon carbide crystals; moreover, due to various impurities, especially transition metal impurities impact, the performance of the crystal is severely degraded, and the wafer cannot be used as a device.
[0005] In summary, the art lacks a process that makes the purity meet the requirements of growing high-quality silicon carbide crystals

Method used

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  • A kind of preparation method of high-purity silicon carbide raw material

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preparation example Construction

[0068] The preparation method of described high-purity silicon carbide raw material comprises the following steps:

[0069] Provide high-purity silicon powder and high-purity carbon powder;

[0070] The high-purity silicon powder and high-purity carbon powder are fully mixed and placed in a crucible to form a silicon carbide material in a high-temperature furnace.

[0071] After the primary silicon carbide material is pulverized, it is oxidized at a high temperature in an oxidation furnace to form a secondary silicon carbide material;

[0072] The secondary silicon carbide material is subjected to high-temperature vacuum degassing in the highest vacuum furnace to form a tertiary silicon carbide material;

[0073] The tertiary silicon carbide material is subjected to wet chemical metallurgical treatment to obtain high-purity silicon carbide raw material.

[0074] In a preferred embodiment, the method for making high-purity silicon carbide (SiC) raw materials of the present in...

Embodiment 1

[0089] Weigh the purity not less than 99.999%, D 50 250 grams of silicon powder with a diameter of 200 μm and a purity of not less than 99.999%, D 50 100 grams of carbon powder with a diameter of 30 μm, placed in a clean plastic container or a polytetrafluoroethylene container, mixed fully and evenly, transferred the mixed powder to a high-purity graphite crucible, placed in an intermediate frequency induction furnace, and evacuated to 5× 10 -4 Pa, then feed argon and hydrogen, the flow rates are 6L / min and 1L / min respectively, and control the pressure in the furnace to keep it at about 50Torr. Heating the crucible to 1800°C at a rate of 800°C / h, kept it warm for 12 hours, and stopped heating. When the temperature in the furnace drops below 500°C, stop the flow supply of argon and hydrogen, and when it cools down to room temperature, take out the graphite crucible, and gently crush the preliminarily synthesized loose silicon carbide to obtain a primary silicon carbide materi...

Embodiment 2

[0094] Weigh the purity not less than 99.999%, D 50 210 grams of silicon powder with a diameter of 200 μm and a purity of not less than 99.999%, D 50 100 grams of carbon powder with a diameter of 90 μm, placed in a clean plastic container or a polytetrafluoroethylene container, mixed fully and evenly, transferred the mixed powder to a high-purity graphite crucible, placed in an intermediate frequency induction furnace, and evacuated to 5× 10 -4Pa, then feed argon and hydrogen, the flow rate is 10L / min and 2L / min respectively, and control the pressure in the furnace to keep at about 100Torr. Heat the crucible to 1900°C at a rate of 800°C / h, keep it warm for 12 hours, and stop heating. When the temperature in the furnace drops below 500°C, stop the flow supply of argon and hydrogen, and when it cools down to room temperature, take out the graphite crucible, and gently crush the preliminarily synthesized loose silicon carbide to obtain a primary silicon carbide material.

[00...

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Abstract

The invention provides a preparation method of a highly pure silicon carbide raw material. The method comprises the following steps: providing highly pure silicon powder and highly pure carbon powder; mixing the highly pure silicon powder with the highly pure carbon powder to obtain a mixture, putting the mixture in a crucible, and forming a primary silicon carbide material in a high temperature furnace having a temperature of 1400-2200DEG C, crushing the primary silicon carbide material, and carrying out high temperature oxidation at 600-1400DEG C to form a secondary silicon carbide material; carrying out high temperature vacuum degassing in a high vacuum furnace at 800-1600DEG C to form a tertiary silicon carbide material; and carrying out wet chemical metallurgical treatment of the tertiary silicon carbide material to obtain the highly pure silicon carbide raw material.

Description

technical field [0001] The invention relates to a method for preparing electronic industry and semiconductor materials, more specifically to a method for preparing silicon carbide raw materials. Background technique [0002] Since American Acheson discovered SiC material in 1891, SiC has many excellent properties, such as high hardness, wear resistance, high temperature resistance, oxidation resistance, corrosion resistance, high thermal conductivity, high chemical stability, broadband Gaps and high electron mobility, etc., are used as raw materials for abrasives, refractory materials, electric heating components, ferrous non-ferrous metal smelting, etc. Among them, abrasives, metallurgy and high-temperature bearing parts are the main application fields of silicon carbide at present, and now they are used in machinery. Structural parts in engineering and seals in chemical engineering, etc., and have very superior performance under extreme conditions such as corrosion, abrasi...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C01B31/36C01B32/984
Inventor 陈建军王辉孔海宽忻隽刘熙肖兵杨建华施尔畏
Owner 安徽微芯长江半导体材料有限公司