Patent ID: 7423316

Claim:
An IGBT comprising: an emitter region of a first conductive type; a body region of a second conductive type, the body region making contact with the emitter region of the first conductive type; a drift region of the first conductive type, the drift region making contact with the body region of the second conductive type and being isolated from the emitter region of the first conductive type by the body region of the second conductive type; a gate electrode facing the body region of the second conductive type via a gate insulator film, the gate electrode passing through the body region of the second conductive type at a portion separating the emitter region of the first conductive type and the drift region of the first conductive type, and extending from the emitter region of the first conductive type to the drift region of the first conductive type; a semiconductor region of the first conductive type having a floating potential, the semiconductor region being formed within the body region of the second conductive type and being isolated from both the emitter region of the first conductive type and the drift region of the first conductive type by the body region of the second conductive type; and a second electrode facing at least a part of the semiconductor region of the first conductive type via an insulator film, and not facing the body region of the second conductive type at a portion separating the semiconductor region of the first conductive type and the emitter region of the first conductive type.