IP Library › Granted Patent US 9,725,823
Granted Patent B2
US 9,725,823 · App. 15/185,602 · Granted Aug 8, 2017

Silicon carbide crystal and method of manufacturing silicon carbide crystal

Inventor: Makoto Sasaki (Itami, JP)
Assignee: Sumitomo Electric Industries, Ltd.
C30B23/025C30B23/00C30B23/02C30B29/36C30B35/007H01L21/02378H01L21/02529H01L21/02631Y10T428/21Y10T428/24355Y10T428/2982
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Quick Facts
Patent No.
US 9,725,823
App. No.
15/185,602
Granted
Aug 8, 2017
Kind
B2
Abstract

An SiC crystal ( 10 ) has Fe concentration not higher than 0.1 ppm and Al concentration not higher than 100 ppm. A method of manufacturing an SiC crystal includes the following steps. SiC powders for polishing are prepared as a first source material ( 17 ). A first SiC crystal ( 11 ) is grown by sublimating the first source material ( 17 ) through heating and precipitating an SiC crystal. A second source material ( 12 ) is formed by crushing the first SiC crystal ( 11 ). A second SiC crystal ( 14 ) is grown by sublimating the second source material ( 12 ) through heating and precipitating an SiC crystal. Thus, an SiC crystal and a method of manufacturing an SiC crystal capable of achieving suppressed lowering in quality can be obtained.

Claims (13)

1. A method of manufacturing a silicon carbide crystal, comprising the steps of:

preparing powders of silicon carbide for polishing as a first source material;

growing a first silicon carbide crystal by sublimating said first source material through heating and precipitating a silicon carbide crystal;

forming a second source material by crushing said first silicon carbide crystal; and

growing a second silicon carbide crystal by sublimating said second source material through heating and precipitating a silicon carbide crystal,

in said step of forming a second source material, said second source material is formed such that a plurality of peaks of size distribution are present in a range not smaller than 1 μm and not greater than 3 mm and 95% or more particles are present in a range of ±50% from a center of each peak of said size distribution.

2. The method of manufacturing a silicon carbide crystal according to claim 1 , wherein

in said step of forming a second source material, said second source material having concentration of iron not lower than 0.002 ppm and not higher than 0.1 ppm and concentration of aluminum not lower than 0.02 ppm and not higher than 100 ppm is formed.

3. The method of manufacturing a silicon carbide crystal according to claim 1 , wherein

said step of forming a second source material includes the step of washing crushed said first silicon carbide crystal with an acid solution.

4. The method of manufacturing a silicon carbide crystal according to claim 1 , further comprising the steps of:

forming a third source material. by crushing said second silicon carbide crystal; and

growing a third silicon carbide crystal by sublimating said third source material through heating and precipitating a silicon carbide crystal.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jun 17, 2016
From: SASAKI, MAKOTO
To: SUMITOMO ELECTRIC INDUSTRIES, LTD.
Reel/Frame 039072/0248 →
Priority Claims (1)
JP 2010-100891 · Apr 26, 2010 · national
Continuity (3)
Division 14019882 · Sep 6, 2013
Continuation 13499482
Related Publication 20160289863A1 · Oct 6, 2016