Patent attributes
An IGBT has layers between emitter and collector sides. The layers include a collector layer on the collector side, a drift layer, a base layer of a second conductivity type, a first source region arranged on the base layer towards the emitter side, a trench gate electrode arranged lateral to the base layer and extending deeper into the drift layer than the base layer, a well arranged lateral to the base layer and extending deeper into the drift layer than the base layer, an enhancement layer surrounding the base layer so as to completely separate the base layer from the drift layer and the well, an electrically conducting layer covering the well and separated from the well by a second electrically insulating layer, and a third insulating layer having a recess on top of the electrically conducting layer such that the electrically conducting layer electrically contacts a emitter electrode.
