Preparation method of kilogram-grade high-purity silicon carbide powder

A pure silicon carbide powder, kilogram-level technology, which is applied in the field of semiconductor material preparation, can solve the problems of high impurity content and the inability to grow semiconductor single crystals, and achieve the effects of saving costs and overcoming uneven heating

Active Publication Date: 2014-04-09
BEIJING CENTURY GOLDRAY SEMICON CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The silicon carbide powder synthesized by this method has an oxide content of 1wt%, and there are hard solid agglomerates, which require crushing, pickling and other processes, resulting in a high impurity content, generally 97%-99%, which cannot reach the level of growing semiconductor single crystals.

Method used

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  • Preparation method of kilogram-grade high-purity silicon carbide powder
  • Preparation method of kilogram-grade high-purity silicon carbide powder
  • Preparation method of kilogram-grade high-purity silicon carbide powder

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0026] 1) Carbon coating: put the graphite crucible into a CVD (chemical vapor deposition) furnace, pass in methane gas, and keep the temperature at 1000°C for 1 hour;

[0027] 2) Plating silicon carbide layer: Mix silicon powder and carbon powder in a molar ratio of 1.05:1 and put them into a carbon-coated graphite crucible. The purity of silicon powder and carbon powder is greater than 99.998%, and the particle size is less than 0.1 mm, put the crucible in a medium-frequency induction heating furnace, pump air into the system, introduce high-purity argon, raise the temperature to 1900°C, keep it for 10 hours, then lower it to room temperature, and take out the reacted product;

[0028] 3) Mixing: mix silicon powder and carbon powder evenly at a molar ratio of 1:1, the purity of both is greater than 99.998%, and the particle size is less than 0.1mm;

[0029] 4) Synthesis: Put the evenly mixed silicon powder and carbon powder into the crucible, put the crucible into the heatin...

Embodiment 2

[0032] 1) Carbon coating: put the graphite crucible into a CVD (chemical vapor deposition) furnace, pass in methane gas, and keep the temperature at 1100°C for 1 hour;

[0033] 2) Plating silicon carbide layer: Mix silicon powder and carbon powder in a molar ratio of 1:1 and put them into a graphite crucible coated with carbon film. The purity of silicon powder and carbon powder is greater than 99.998%, and the particle size is less than 0.1 mm, put the crucible in a medium-frequency induction heating furnace, pump air into the system, introduce high-purity argon, raise the temperature to 1800°C, keep it for 10 hours, then lower it to room temperature, and take out the reacted product;

[0034] 3) Mixing: mix silicon powder and carbon powder evenly at a molar ratio of 1:1, the purity of both is greater than 99.998%, and the particle size is less than 0.1mm;

[0035] 4) Synthesis: Put the evenly mixed silicon powder and carbon powder into the crucible, put the crucible into the...

Embodiment 3

[0038] 1) Carbon coating: put the graphite crucible into a CVD (chemical vapor deposition) furnace, pass in methane gas, and keep the temperature at 1200°C for 1 hour;

[0039] 2) Silicon carbide coating layer: Mix silicon powder and carbon powder in a molar ratio of 1:1 and put them into the graphite crucible coated with carbon film. The purity of silicon powder and carbon powder is greater than 99.998%, and the particle size is less than 0.1 mm, place the crucible in a medium-frequency induction heating furnace, pump air into the system, introduce high-purity argon, raise the temperature to 2000°C, keep it for 10 hours, then lower it to room temperature, and take out the reacted product;

[0040] 3) Mixing: mix silicon powder and carbon powder evenly at a molar ratio of 1:1, the purity of both is greater than 99.998%, and the particle size is less than 0.1mm;

[0041] 4) Synthesis: Put the evenly mixed silicon powder and carbon powder into the crucible, put the crucible into...

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PUM

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Abstract

The invention provides a preparation method of kilogram-grade high-purity silicon carbide powder, and the preparation method comprises the following steps: (1) coating a graphite crucible with a carbon film; (2) coating the graphite crucible coated with the carbon film with silicon carbide, (3) putting mixed silicon powder and carbon powder into the crucible, putting the crucible in a heating pipe, putting the heating pipe into a medium-frequency induction heating furnace, pumping air out of the system, heating, filling high-purity argon, helium or a hydrogen and argon mixed gas, heating to the synthesis temperature, keeping warm for a certain time, and then cooling to obtain the kilogram-grade high-purity silicon carbide powder. The method can effectively remove the majority of impurity elements in the silicon powder and the carbon powder, can eliminate interferences of non intentionally doped impurities on high-purity half-insulating silicon carbide single crystal growth or N-type doping and P-type doping silicon carbide single crystal growth, and is conducive to stabilizing crystal type, resistivity and other electrical parameters.

Description

technical field [0001] The invention relates to a method for preparing high-purity silicon carbide powder, which belongs to the technical field of semiconductor material preparation. Background technique [0002] As a wide bandgap semiconductor material, silicon carbide single crystal has excellent physical and electrical properties such as high thermal conductivity, high breakdown field strength, and high saturation electron drift rate. It is widely used in aerospace, ocean exploration, radar communication, and automotive electronics. The field has great application prospects. [0003] At present, the physical gas phase transport method is generally used for growing silicon carbide single crystals, that is, the raw materials are sublimated into gas phase substances in the high temperature area, and the gas phase substances are transported to the surface of the seed crystal with a certain distance from the surface of the raw material and at a lower temperature under the acti...

Claims

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Application Information

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IPC IPC(8): C01B31/36C01B32/956
Inventor 何丽娟
Owner BEIJING CENTURY GOLDRAY SEMICON CO LTD
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