Silicon carbide semiconductor device and manufacturing method therefor

摘要

All of intervals between adjacent p type guard rings are set to be equal to or less than an interval between p type deep layers. As a result, the interval between the p type guard rings becomes large, i.e., the trenches are formed sparsely, so that the p type layer is prevented from being formed thick at the guard ring portion when the p type layer is epitaxially grown. Therefore, by removing the p type layer in the cell portion at the time of the etch back process, it is possible to remove the p type layer without leaving any residue in the guard ring portion. Therefore, when forming the p type deep layer, the p type guard ring and the p type connection layer by etching back the p type layer, the residue of the p type layer is restricted from remaining in the guard ring portion.