Patent ID: 9536998
Date: 2017-01-03
CPC Classifications: H01L

Claim:
1. A semiconductor device comprising: a semiconductor layer of a first conductive type formed thereon with a gate trench; a gate insulating film formed on a side surface and on a bottom surface of the gate trench, the gate insulating film integrally including a side-surface insulating film on the side surface and a bottom-surface insulating film on the bottom surface; and a gate electrode embedded in the gate trench, the gate electrode selectively having an overlap portion overlapping the surface of the semiconductor layer in an upper edge formed at an opening end of the gate trench, wherein the side-surface insulating film includes an overhung portion selectively thicker than other portions of the side-surface insulating film so as to protrude inwardly of the gate trench at the upper edge, the semiconductor layer includes an active region in which a trench gate type MIS transistor is formed and an inactive region outside the active region and in which the overhung portion is formed, and in the active region, the semiconductor layer further includes: