Patent ID: 8164116
Filing Date: 2012-04-24
Classification: H01L

Abstract:
1. A semiconductor device, comprising: a semiconductor base of a first conductivity type; a hetero semiconductor region of a second conductivity type in contact with one main surface of the semiconductor base, the hetero semiconductor region having a band gap width different from that of the semiconductor base; a first electrode connected to the hetero semiconductor region; and a second electrode connected to the semiconductor base, wherein the hetero semiconductor region comprises structure for reducing leakage current generated during reverse operation, wherein the hetero semiconductor region is formed of a laminated hetero semiconductor region in which a plurality of semiconductor layers are superposed on one another, and wherein an uppermost semiconductor layer of the laminated hetero semiconductor region is connected to the first electrode, a lowest layer of the laminated hetero semiconductor region is in contact with the semiconductor base, and the uppermost semiconductor layer is in direct contact with the semiconductor base, and wherein the uppermost semiconductor layer has higher impurity concentration than the lowest layer.