SILICON CARBIDE SEMICONDUCTOR DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a silicon carbide semiconductor device which has a high withstand voltage.SOLUTION: A silicon carbide semiconductor device comprises: a drift layer 81 which forms a first principal surface P1 of a silicon carbide layer 101 and has a first conductivity type; a source region 83 which is provided in such a manner to be separated from the drift layer 81 by a body region 82 and which forms a second principal surface P2 and has the first conductivity type; and a relaxation region 71 which is provided within the drift layer 81 and has a distance Lfrom the first principal surface P1. The relaxation region 71 has a second conductivity type and an impurity dose amount D. The drift layer 81 has an impurity concentration Nbetween the first principal surface P1 and the relaxation region 71. The relational expression D>L×Nis satisfied.