Silicon carbide crystal and method of manufacturing silicon carbide crystal
AssigneeSumitomo Electric Industries, Ltd.
InventorMakoto Sasaki
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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 SiC 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, an SiC crystal and a method of manufacturing an SiC crystal capable of achieving suppressed lowering in quality can be obtained.
Claims5
A silicon carbide crystal comprising a seed substrate and a grown crystal portion formed on said seed substrate,
- said grown crystal portion 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/cm2, and
- the micropipe density of said grown crystal portion with respect to micropipe density of said seed substrate being less than 40%.
A method of manufacturing a silicon carbide crystal comprising a seed substrate and a grown crystal portion formed on said seed substrate, 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 on said seed substrate 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 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,
- and said grown second silicon carbide crystal having micropipe density not higher than 2/cm2, and the micropipe density of said grown second silicon carbide crystal with respect to micropipe density of said seed substrate being less than 40%.”
Dependencies are inferred from the claim text.