Patent ID: 7859048
Filing Date: 2010-12-28
Classification: H01L

Abstract:
1. A semiconductor device comprising: a first semiconductor layer having a first conductive type; a PN column layer disposed on the first semiconductor layer; and a second semiconductor layer having a second conductive type and disposed on the PN column layer, wherein the PN column layer includes a first column layer and a second column layer, wherein the first column layer is disposed on the first semiconductor layer, and the second column layer is disposed between the first column layer and the second semiconductor layer, wherein each of the first column layer and the second column layer includes a first column having the first conductive type and a second column having the second conductive type, wherein the first column and the second column in the first column layer are alternately arranged along with a horizontal direction parallel to a first boundary between the PN column layer and the first semiconductor layer, wherein the first column and the second column in the second column layer are alternately arranged along with the horizontal direction parallel to a second boundary between the PN column layer and the second semiconductor layer, wherein the first column layer has a first impurity amount difference, which is defined at a predetermined depth from the first boundary by subtracting an impurity amount in the second column from an impurity amount in the first column, wherein the second column layer has a second impurity amount difference, which is defined at a predetermined depth from a second boundary between the PN column layer and the second semiconductor layer by subtracting an impurity amount in the second column from an impurity amount in the first column, wherein the first impurity amount difference is constant and positive, and wherein the second impurity amount difference is constant and negative.