Patent ID: 7719053

Claim:
A semiconductor device, comprising: a semiconductor region of a first conduction type; a first main electrode connected to said semiconductor region; a base region of a second conduction type formed on said semiconductor region; a diffused region of the first conduction type formed on said base region; a second main electrode connected to said diffused region and said base region; a first trench formed extending from a surface of said diffused region to said semiconductor region; a second trench formed from a center of a bottom of said first trench, the second trench being much deeper than said first trench and being smaller in lateral width than said first trench; a gate electrode formed on a side of said first trench via a first insulator film; and a protruded electrode formed in said second trench via a second insulator film as protruded downward lower than said gate electrode, said protruded electrode being electrically and directly connected to said second main electrode.