Patent ID: 8592917

Claim:
A semiconductor device, comprising: a first semiconductor layer having a first conductivity type; a second semiconductor layer provided on the first semiconductor layer and including first pillars of the first conductivity type and second pillars of a second conductivity type, the first pillars and the second pillars being provided alternately along a major surface of the first semiconductor layer; a first control electrode provided in a trench via a first insulating layer, the trench being provided from a surface of the second semiconductor layer toward the first semiconductor layer; a second control electrode provided on the second semiconductor layer via a second insulating layer and connected to the first control electrode; a first semiconductor region of the second conductivity type provided on a surface of the second semiconductor layer except for a portion under the second control electrode; a second semiconductor region of the first conductivity type provided selectively on a surface of the first semiconductor region, the second semiconductor region being apart from the portion of the second semiconductor layer under the second control electrode; a third semiconductor region of the second conductivity type provided selectively on the first semiconductor region by neighboring the second semiconductor region; a first major electrode connected electrically to the first semiconductor layer; and a second major electrode connected electrically to the second semiconductor region and the third semiconductor region.