Patent ID: 8552423

Claim:
A semiconductor device comprising: a driver circuit including a first transistor over a substrate; and a pixel including a second transistor over the substrate, wherein the first transistor and the second transistor each comprise: a first gate electrode layer; a gate insulating layer over the first gate electrode layer; an oxide semiconductor layer over the gate insulating layer; a source electrode layer over the oxide semiconductor layer; a drain electrode layer over the oxide semiconductor layer; and an oxide insulating layer over the gate insulating layer, the oxide semiconductor layer, the source electrode layer, and the drain electrode layer, the oxide insulating layer being in contact with at least a channel formation region in the oxide semiconductor layer, wherein the channel formation region overlaps with the first gate electrode layer with the gate insulating layer therebetween, wherein, in the second transistor, each of the first gate electrode layer, the gate insulating layer, the oxide semiconductor layer, the source electrode layer, the drain electrode layer, and the oxide insulating layer has a light-transmitting property, wherein the first transistor further comprises a second gate electrode layer overlapping with the first gate electrode layer, wherein the pixel further comprises a pixel electrode electrically connected to one of the source electrode layer and the drain electrode layer of the second transistor, and wherein the pixel electrode overlaps with all of the oxide semiconductor layer of the second transistor.