Patent ID: 6979845
Filing Date: 2005-12-27
Classification: H01L

Abstract:
1. A semiconductor device comprising: a semiconductor region of a first conductive type; first and second regions of a second conductive type opposite to the first conductive type, wherein said first and second regions are provided in a surface of said semiconductor region in a predetermined interval; a third region of said first conductive type which is provided between said first and second regions in said surface of said semiconductor region; and a fourth region of said first conductive type which is provided below said third region inside said semiconductor region to cover the whole of bottom of said third region at least; wherein a position of an impurity peak concentration of said fourth region into a depth direction is deeper than a peak position of an impurity concentration in each of said first and second regions into the depth direction; wherein a minimum of an impurity peak concentration of said fourth region is (1−s)*1.4E16 (atom/cm