Patent ID: 9070658
Filing Date: 2015-06-30
Classification: H01L

Abstract:
1. A semiconductor device comprising: a first semiconductor layer of a first-conductivity-type; a second semiconductor layer of second-conductivity-type that is provided on a first main surface of the first semiconductor layer and has an impurity concentration more than that of the first semiconductor layer; a third semiconductor layer of the first-conductivity-type that is provided on a second main surface of the first semiconductor layer and has an impurity concentration more than that of the first semiconductor layer; and a broad buffer layer of the first conductivity-type that is provided in the first semiconductor layer and has an impurity concentration more than that of the first semiconductor layer, and has a mound-shaped impurity concentration distribution in which a local maximum value is less than the impurity concentration of the second semiconductor layer and the third semiconductor layer, the mound-shaped impurity concentration distribution having a peak at the local maximum value and differences of elevation in a depth direction, wherein a resistivity ρ