Patent ID: 9263259
Filing Date: 2016-02-16
CPC Classification: H01L

Claim Text:
1. A semiconductor device comprising: an oxide insulating film; an oxide semiconductor layer over the oxide insulating film; a first source electrode layer in contact with the oxide semiconductor layer; a first drain electrode layer in contact with the oxide semiconductor layer; a second source electrode layer in contact with the oxide semiconductor layer, the second source electrode layer covering the first source electrode layer; a second drain electrode layer in contact with the oxide semiconductor layer, the second drain electrode layer covering the first drain electrode layer; a gate insulating film over the oxide semiconductor layer, the second source electrode layer, and the second drain electrode layer; a first gate electrode layer over the gate insulating film; a second gate electrode layer over the first gate electrode layer; and a protective insulating film over the second gate electrode layer, wherein the gate insulating film is in contact with the oxide insulating film, wherein each of the second source electrode layer, the second drain electrode layer, and the first gate electrode layer comprises nitrogen, wherein the oxide insulating film has a concave portion on a side more outer than an edge of the first source electrode layer, and wherein the oxide insulating film is in contact with the second source electrode layer at the concave portion.