US Patent 7723783 Semiconductor device

A semiconductor device includes: a first semiconductor layer of a first conductivity type; a first semiconductor region of the first conductivity type and a second semiconductor region of a second conductivity type alternately arranged in a lateral direction on the first semiconductor layer of the first conductivity type; a third semiconductor region of the second conductivity type formed on the first semiconductor region; a fourth semiconductor region of the first conductivity type formed on a portion of the surface of the third semiconductor region; a control electrode provided via an first insulating film in a groove formed in contact with the fourth semiconductor region, the third semiconductor region, and the first semiconductor region; a first main electrode electrically connected to the first semiconductor layer; a second main electrode forming a junction with the third and fourth semiconductor region; and a fifth semiconductor region of the second conductivity type. The fifth semiconductor region is formed in contact with the first insulating film, the first semiconductor region, and the second semiconductor region. The bottom face of the fifth semiconductor region is deeper than the bottom face of the control electrode. Alternatively, the fifth semiconductor region may be spaced apart from the first insulating film.