SILICON CARBIDE SUBSTRATE, MANUFACTURE THEREOF AND SILICON CARBIDE SEMICONDUCTOR DEVICE USING THE SAME SUBSTRATE

摘要

PROBLEM TO BE SOLVED: To eliminate characteristic dispersion of a silicon carbide semiconductor device using a substrate having an epitaxially grown low-concn. silicon carbide layer on a silicon carbide base. SOLUTION: The surface of a silicon carbide base 1 is etched, a conductivity correcting layer 2 having the same conductivity type as that of the base 1 and approximately the same impurity concn. is laminated 3μm or more, and a low-concn. layer 3 is laminated thereon. Crystal defects from the base 1 stop from propagating in the conductivity correcting layer 2 to result in a low-concn. layer 3 which is good in crystallinity. In this layer 2, the influence of the crystal defects on the electric conductivity is masked by a doped high concn. impurity.