Patent ID: 9276121
Filing Date: 2016-03-01
CPC Classification: H01L

Claim Text:
1. A semiconductor device comprising: a first insulating film containing aluminum oxide; a conductive layer over the first insulating film; a first oxide insulating film over the conductive layer, wherein the first oxide insulating film, and wherein an upper surface of the first oxide insulating film is planarized; an oxide semiconductor layer comprising a channel formation region over the planarized surface of the first oxide insulating film, wherein the channel formation region overlaps with the conductive layer; a source electrode layer and a drain electrode layer electrically connected to the oxide semiconductor layer; a gate insulating film over the oxide semiconductor layer; a gate electrode layer over the channel formation region with the gate insulating film interposed therebetween; and a second insulating film containing aluminum oxide over the oxide semiconductor layer, the source electrode layer, the drain electrode layer, and the gate electrode layer, wherein the first oxide insulating film comprises a first region which overlaps with the conductive layer, and a second region which does not overlap with the conductive layer, wherein a first thickness of the first oxide insulating film in the first region is smaller than a second thickness of the first oxide insulating film in the second region, wherein the first insulating film is in direct contact with the second insulating film, and wherein the conductive layer, the first oxide insulating film, the oxide semiconductor layer, the source electrode layer, the drain electrode layer, the gate insulating film, and the gate electrode layer are between the first insulating film and the second insulating film.