US Patent 7323728 Semiconductor device

Disclosed is a semiconductor device including an n+-type semiconductor layer formed on a substrate, a first n-type semiconductor layer formed on the n+-type semiconductor layer, a p-type semiconductor layer formed on the first n-type semiconductor layer and having a material having a first band gap, a second n-type semiconductor layer formed on the p-type semiconductor layer, being smaller than the p-type semiconductor layer in area and having a material having a second band gap larger than the first band gap, an implant portion formed to penetrate the p-type semiconductor layer, the first n-type semiconductor layer, and the n+-type semiconductor layer in a region where the second n-type semiconductor layer is not formed and to divide these layers into two regions, and an electrode formed on a region of the p-type semiconductor layer where the second n-type semiconductor layer is not formed, so as to bridge over the implant portion.