Silicon carbide crystal and method of manufacturing silicon carbide crystal

Abstract

An SiC crystal 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. A first crystal is grown by sublimating the first source material through heating and precipitating an SiC crystal. A second source material is formed by crushing the first SiC crystal. A second SiC crystal is grown by sublimating the second source material through heating and precipitating an SiC crystal. Thus, SiC crystal and a method of manufacturing an SiC crystal capable of achieving suppressed lowering in quality can be obtained.

1 . A silicon carbide crystal, 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, and having micropipe density not higher than 2/cm 2 . 
     
     
         2 . (canceled) 
     
     
         3 . The silicon carbide crystal according to  claim 1 , having etch pit density not lower than 4100/cm 2  and not higher than 5200/cm 2 . 
     
     
         4 . 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.   
     
     
         5 . (canceled) 
     
     
         6 . The method of manufacturing a silicon carbide crystal according to  claim 4 , 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.   
     
     
         7 . The method of manufacturing a silicon carbide crystal according to  claim 4 , wherein
 said step of forming a second source material includes the step of washing crushed said first silicon carbide crystal with an acid solution.   
     
     
         8 . The method of manufacturing a silicon carbide crystal according to  claim 4 , 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.