Patent ID: 8304814

Claim:
A bipolar power semiconductor device comprising: an emitter electrode arranged on an emitter side; a collector electrode arranged on a collector side, which lies opposite to the emitter side; a trench gate electrode and a structure with a plurality of layers of different conductivity types, the trench gate electrode and the layers being arranged in planes parallel to the emitter side and each comprising a bottom, which is arranged in a maximum distance from the emitter side, to which the gate electrode or the layer extends, respectively; at least one source region of a first conductivity type which is arranged on the emitter side and which contacts the emitter electrode; a base layer of a second conductivity type which is arranged on the emitter side, surrounds the at least one source region and contacts the emitter electrode and the at least one source region; a collector layer of the second conductivity type which is arranged on the collector side and which contacts the collector electrode; a drift layer of the first conductivity type arranged between the base layer and the collector layer; an insulation layer electrically insulating the trench gate electrode from the source region, the base layer and the drift layer, the trench gate electrode being arranged in the same plane as the base layer, and the trench gate electrode including a gate bottom; an enhancement layer of the first conductivity type and a well layer of the second conductivity type, which are arranged between the base layer and the drift layer, the enhancement layer adjoining the base layer towards the collector side, and the well layer adjoining the enhancement layer towards the collector side; a first additional well layer of the second conductivity type which adjoins the drift layer towards the emitter side; and a first additional enhancement layer of the first conductivity type which adjoins the first additional well layer towards the emitter side and which extends to an additional enhancement layer bottom, wherein the gate bottom of the trench gate electrode is located closer to the collector side than the additional enhancement layer bottom.