Patent ID: 7476942

Claim:
A SOI lateral semiconductor device comprising: a semiconductor substrate of a first conductivity type; a buried insulator film in the semiconductor substrate; a very resistive active layer of a second conductivity type on the buried insulator film, the buried insulator film insulating and separating a major portion of the active layer from the semiconductor substrate; a first semiconductor region of the first conductivity type formed adjacent to a first end of the active layer; a second semiconductor region of the second conductivity type formed adjacent to a second end of the active layer, the second semiconductor region extending more deeply in the substrate than the buried insulator film; a buffer region of the second conductivity type in the active layer, the buffer region being less electrically resistive than the active layer; a third semiconductor region of the first conductivity type in the buffer region, the third semiconductor region extending from the surface of the buffer region toward the buried insulator film; a fourth semiconductor region of the second conductivity type in a surface portion of the first semiconductor region; a gate electrode over the first semiconductor region and extending between the fourth semiconductor region and the active layer with a gate oxide film beneath the gate electrode; a metal electrode over and in contact with the third semiconductor region; a metal electrode over the fourth semiconductor region; and a metal electrode over and in contact with the second semiconductor region.