Patent ID: 9589951
Date: 2017-03-07
CPC Classifications: H01L

Claim:
1. A semiconductor device, comprising: a semiconductor substrate composed of silicon; a first nitride semiconductor layer of a first conductivity type provided over the semiconductor substrate; a second nitride semiconductor layer provided over the first nitride semiconductor layer; a first semiconductor region of a second conductivity type opposite to the first conductivity type, the first semiconductr region being provided in the second nitride semiconductor layer; a second semiconductor region of the second conductivity type provided in the second nitride semiconductor layer separately from the first semiconductor region in plan view; a first film part including of an insulator and a nitride semiconductor, and provided over part of the second nitride semiconductor layer located between the first semiconductor region and the second semiconductor region; a gate electrode provided over the first film part; a source electrode electrically coupled to the first semiconductor region; and a drain electrode electrically coupled to the second semiconductor region, wherein each of the first semiconductor region and the second semiconductor region is in contact with the first nitride semiconductor layer, a first nitride semiconductor region is provided over part of the second nitride semiconductor layer located between the first semiconductor region and the first film part; a second nitride semiconductor region is provided over part of the second nitride semiconductor layer located between the second semiconductor region and the first film part, a bandgap of the first nitride semiconductor region and a bandgap of the second nitride semiconductor region are each wider than a bandgap of the second nitride semiconductor layer, and the first film part includes a first insulting film provided over part of the second nitride semiconductor layer located between the first nitride semiconductor region and the second nitride semiconductor region, said semiconductor device further comprising a third nitride semiconductor layer provided over the semiconductor substrate, and exhibiting spontaneous polarization, wherein the first nitride semiconductor layer is provided over the third nitride semiconductor layer, wherein the second nitride semiconductor layer exhibits spontaneous polarization, and wherein the amount of spontaneous polarization of the third nitride semiconductor layer is larger than the amount of spontaneous polarization of the second nitride semiconductor layer.