| 摘要 |
<p>An object of the present invention is to provide a MOS type semiconductor device allowing production at a low cost without lowering a breakdown voltage and avoiding increase of an ON resistance. A MOS type semiconductor device of the invention comprises: a p base region having a bottom part in a configuration with a finite radius of curvature and selectively disposed on a front surface region of a n−drift layer; an n type first region selectively disposed on a front surface region of the p base region; a gate electrode disposed on a part of the surface of the p base region between a surface of the n type first region and a front surface of the n−drift layer interposing a gate insulation film between the part of the surface of the p base region and the gate electrode; and a metal electrode in electrically conductive contact with the front surface of the n type first region and the central part of the surface of the p base region; wherein a pn junction surface between the base region and the drift layer has centers of curvature both at the outside and inside of the base region.</p> |
