Patent ID: 7741655
Filing Date: 2010-06-22
Classification: H01L

Abstract:
1. A semiconductor device, comprising: a semiconductor substrate having an upper and a lower surface; and a semiconductor element having an insulated gate field effect portion formed in said semiconductor substrate; said semiconductor element including a first region of a first conductivity type formed in said semiconductor substrate, a source region of the first conductivity type formed in said semiconductor substrate at the upper surface, a base region of a second conductivity type formed in said semiconductor substrate at the upper surface, and surrounding said source region, a second region of the first conductivity type formed in said semiconductor substrate at the upper surface, the second region being in contact with said base region on a inner side facing the source region, and being in contact with the first region on an outer side opposite to the inner side, and being opposed to said source region with said base region being interposed, and having an impurity concentration higher than that of said first region, an insulating film formed on said base region located between said source region and said second region, and a gate electrode formed on said insulating film, wherein said first region being adjacent to said base region and to said second region.