Patent ID: 8304901

Claim:
A semiconductor device, comprising: a semiconductor layer of a first conductivity type; an electrode formed on a main surface of said semiconductor layer; a guard ring layer of a second conductivity type formed from a part of said main surface of said semiconductor layer directly below an end portion of said electrode and extending toward an inside of said semiconductor layer so as to surround said electrode; at least one groove formed from a part of said main surface of said semiconductor layer located at a distance outside said end portion of said electrode and extending toward the inside of said semiconductor layer so as to surround, without touching, said guard ring layer; at least one junction termination extension (JTE) layer of said second conductivity type formed from a bottom of said at least one groove and extending toward an interior of said semiconductor layer so as to surround, without touching, said guard ring layer; and an insulating film formed on said main surface of said semiconductor layer so as to cover a surface of said guard ring layer and a surface of said at least one JTE layer.