Patent ID: 7285824

Claim:
A semiconductor device comprising: a semiconductor layer of a first conductivity type; a first semiconductor region of a second conductivity type provided on the semiconductor layer, the first semiconductor region being one of an anode region and a cathode region; a second semiconductor region of the first conductivity type provided on the first semiconductor region, the second semiconductor region being the other of the anode region and the cathode region; a semiconductor buried region of the second conductivity type provided between the semiconductor layer and the first semiconductor region; a third semiconductor region of the second conductivity type provided on the semiconductor layer to adjoin the first semiconductor region and connected to the buried region; a first main electrode connected to the third semiconductor region; a second main electrode connected to the second semiconductor region; and a common electrode connected to the semiconductor layer, the semiconductor buried region having an aperture where the first semiconductor region is in contact with the semiconductor layer, the aperture being surrounded by the semiconductor buried region of the second conductivity type.