Patent ID: 7531871

Claim:
A semiconductor element comprising: a semiconductor substrate of a first conductivity type having a first major surface and a second major surface opposing the first major surface; a drift layer of the first conductivity type formed on the first major surface of said semiconductor substrate; a well layer of a second conductivity type selectively formed in a upper surface of said drift layer; a source layer of the first conductivity type selectively formed in a upper surface of said well layer; a trench formed to reach an inside of said semiconductor substrate from an upper surface of said source layer through said well layer and said drift layer; a buried electrode formed in said trench through a first insulating film; a control electrode formed on the uppermost surface of said drift layer, and the uppermost surface of said well layer through a second insulating film; a first main electrode formed on the second major surface of said semiconductor substrate; and a second main electrode connected to said source layer and said well layer, a part of the first insulating film being formed between an upper surface of the buried electrode and a bottom surface of the second main electrode and being directly contacted with the bottom surface of the second main electrode.