Patent ID: 7470956
Filing Date: 2008-12-30
Classification: H01L

Abstract:
1. A semiconductor device, comprising a semiconductor base comprising: a substrate; an insulating film formed on said substrate; a first semiconductor region having a first conductivity type formed on said insulating film; a diffusion layer formed between said first semiconductor region and said insulating film; a second semiconductor region having the first conductivity type formed on a surface region of said first semiconductor region; and a third semiconductor region having a second conductivity type formed on a surface region of said first semiconductor region so as to face said second semiconductor region via said first semiconductor region; said third semiconductor region adjoining to said first semiconductor region, while not adjoining to said second semiconductor region; a first electrode formed on said second semiconductor region of said semiconductor base, and a second electrode formed on said third semiconductor region of said semiconductor base, wherein said semiconductor device further comprises said diffusion layer on a surface of said first semiconductor region contacting said insulating layer, said diffusion layer having a gradient of concentration of an impurity having the first conductivity type, from a side of said first electrode to a side of said second electrode.