Patent ID: 7491982
Filing Date: 2009-02-17
Classification: H01L

Abstract:
1. A semiconductor device, comprising: a semiconductor substrate of the first conductivity type having a first surface and a second surface; a base region of the second conductivity type formed on the first surface of the semiconductor substrate; a guard ring region of the second conductivity type forming an encircling structure laterally surrounding the base region, and having a second conductivity type impurity of which concentration is lower than that of the base region; a first electrode formed on the base region; a second electrode formed on the second surface of the semiconductor substrate; a base peripheral region forming an encircling structure laterally surrounding the base region and being connected to the base region, wherein the base peripheral region is deeper than the base region and has the substantially constant depth, and the concentration of the second conductivity type impurity included in the base peripheral region is lower than that included in the base region; and an insulating layer covering at least a portion of an upper surface of the base peripheral region, the insulating layer interposed between the base peripheral region and at least a portion of the first electrode.