A fast and selective method for reducing micropipe and dislocation density in SiC crystals

A selective, crystallographic technology, applied in the direction of chemical instruments and methods, crystal growth, single crystal growth, etc., can solve the problems that the dislocation density cannot be reduced, there is no effective method, and the micropipe and dislocation density can be reduced to achieve shortening Optimize time, optimize single crystal quality, and reduce genetic effects

Inactive Publication Date: 2020-12-08
SHANDONG UNIV +2
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Although the dislocation density distribution can be changed by doping, the dislocation density cannot be reduced
[0005] It can be seen that there is still no effective way to improve the quality of SiC single crystals and reduce the density of micropipes and dislocations at this stage.

Method used

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  • A fast and selective method for reducing micropipe and dislocation density in SiC crystals
  • A fast and selective method for reducing micropipe and dislocation density in SiC crystals
  • A fast and selective method for reducing micropipe and dislocation density in SiC crystals

Examples

Experimental program
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Effect test

Embodiment 1

[0039] A method for rapidly and selectively reducing the density of micropipes and dislocations in SiC crystals, comprising the following steps:

[0040] (1) Select the microtubule density -2 , dislocation density ≤10 3 cm -2 The SiC region of the crystal is cut into a 6-fold symmetrical crystal whose side is a polar surface, and the cut crystal is polished to remove the cut damage layer;

[0041] (2) The symmetric crystal treated in step (1) is fixed on the multi-micropipe multi-dislocation region of the SiC seed crystal with graphite glue. The crystal form of the crystal in step (1) is the same as that of the SiC seed crystal in step (2). consistent type;

[0042] (3) The SiC seed crystal treated in step (2) is subjected to two-stage crystal growth, the first stage: low temperature and low pressure to promote lateral growth, the low temperature and low pressure growth temperature is 1700°C, the pressure is 1mbar, and the growth time is 10h; Microtubule density -2 , disloc...

Embodiment 2

[0050] A method for rapidly and selectively reducing the density of micropipes and dislocations in SiC crystals, comprising the following steps:

[0051] (1) Select the microtubule density -2 , dislocation density ≤10 3 cm -2 The SiC region of the crystal is cut into a 3-fold symmetrical crystal whose side is a polar surface, and the cut crystal is polished to remove the cut damage layer;

[0052] (2) The symmetric crystal treated in step (1) is fixed on the multi-micropipe multi-dislocation region of the SiC seed crystal with graphite glue. The crystal form of the crystal in step (1) is the same as that of the SiC seed crystal in step (2). consistent type;

[0053] (3) The SiC seed crystal treated in step (2) is subjected to two-stage crystal growth, the first stage: low temperature and low pressure to promote lateral growth, the low temperature and low pressure growth temperature is 1900°C, the pressure is 2mbar, and the growth time is 8h; Microtubule density -2 , disloca...

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PUM

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Abstract

The invention relates to a fast and selective method for reducing the densities of micro-tubes and dislocations in SiC crystals. A SiC region with the micro-tube density of less than 1 cm<-2> and thedislocation density of less than or equal to 5000 cm<-2> is used for covering a region with high densities of the micro-tubes and dislocations, so the extension of the dislocations and micro-tubes isblocked, the inheritance of the dislocations and micro-tubes is reduced effectively, SiC bulk single crystals with specific micro-tube and dislocation densities can be obtained and have high selectivity, the bulk single crystals with low densities of the micro-tubes and dislocations can be obtained by only once growth, and the optimization time is greatly shortened.

Description

technical field [0001] The invention relates to a method for rapidly and selectively reducing the density of micropipes and dislocations in SiC crystals, belonging to the technical field of crystal growth. Background technique [0002] As a third-generation semiconductor material, SiC single crystal material has excellent electrical properties including wide bandgap, high thermal conductivity, high electron saturation migration rate, and high breakdown electric field. The ideal semiconductor material for power electronic devices is widely used in white light lighting, optical storage, screen display, aerospace, high temperature radiation environment, oil exploration, automation, radar and communication, automotive electronics, etc. Currently the most successful and commercialized method for growing SiC crystals is still the physical vapor transport (PVT) method. [0003] With the gradual improvement of the quality of SiC single crystal, the diameter of SiC becomes larger an...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C30B29/36C30B23/00
CPCC30B23/00C30B29/36
Inventor 彭燕陈秀芳杨祥龙徐现刚胡小波张用张磊
Owner SHANDONG UNIV
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