Manufacturing process of a high integration density power mos device

Abstract

Process of manufacturing a semiconductor device comprising a step of forming recessed zones in a semiconductor layer of a first conductivity type, a step of oxidation for forming a gate oxide layer at the sidewalls of the recessed zones, a step of forming a polysilicon gate electrode inside the recessed zones, a step of forming body regions of a second conductivity type in the semiconductor layer between the recessed zones, and a step of forming source regions of the first conductivity type in the body regions. The step of forming recessed zones comprises a step of local oxidation of the surface of the semiconductor layer wherein the recessed zones will be formed, with an oxide growth at the semiconductor layer's cost in order to obtain thick oxide regions penetrating in the semiconductor layer, and a step of etching wherein the oxide of the thick oxide regions is removed.

Dependencies are inferred from the claim text.