Power semiconductor device with gate having v-groove upper surface and method of manufacturing thereof

Abstract

An object of the present disclosure is to provide a trench gate type power semiconductor device that does not easily break even when stress is applied. A SiC-MOSFET includes a SiC substrate, a drift layer of a first conductive type, formed on the SiC substrate, a base region of a second conductivity type formed in a surface layer of the drift layer, a source region of the first conductivity type selectively formed in a surface layer of the base region, a trench extending through the base region and the source region and reaching the drift layer, a gate electrode embedded in the trench and having a V-shaped groove on an upper surface thereof, and an oxide film formed on an upper surface including the groove of the gate electrode, in which a bottom of the V-shape groove is deeper than the base region.