Patent ID: 8618557

Claim:
A wide-band-gap reverse-blocking MOS-type semiconductor device comprising: a wide-band-gap semiconductor layer of a first conductivity type; a semiconductor substrate of a second conductivity type on a side of a first major surface of the wide-band-gap semiconductor layer; a trench formed through the semiconductor substrate, the trench extending into the wide-band-gap semiconductor layer; a metal film in a bottom of the trench, the metal film contacting with the wide-band-gap semiconductor layer for forming a Schottky junction; an active section comprising a MOS-gate structure, the active section being on a side of a second major surface of the wide-band-gap semiconductor layer facing to an area, therein the Schottky junctions are formed; a breakdown withstanding section surrounding the active section; and a trench isolation layer surrounding the breakdown withstanding section, the trench isolation layer extending from the second major surface of the wide-band-gap semiconductor layer into the semiconductor substrate, the trench isolation layer comprising an insulator film buried therein.