Patent ID: 7268392
Filing Date: 2007-09-11
Classification: H01L

Abstract:
1. A semiconductor device comprising: a first semiconductor region of a first conductivity type; a second semiconductor region of a second conductivity type provided on the first semiconductor region; a trench formed in the second semiconductor region; a thick gate insulating film selectively provided in a center area of a bottom surface of the trench; a thin gate insulating film provided along a periphery of the bottom surface and on a sidewall of the trench; a third semiconductor region of the first conductivity type that is selectively provided below the thin gate insulating film provided along the periphery of the bottom surface of the trench and that extends to the first semiconductor region; a fourth semiconductor region of the first conductivity type selectively provided in the surface of the second semiconductor region; and a gate electrode filling the trench via the gate insulating film.