Patent ID: 8106400
Filing Date: 2012-01-31
Classification: H01L

Abstract:
1. A semiconductor device comprising: a pixel portion and a driver circuit, wherein the pixel portion includes at least a first thin film transistor having a first oxide semiconductor layer, wherein the driver circuit includes at least a second thin film transistor having a second oxide semiconductor layer and a third thin film transistor having a third oxide semiconductor layer are included, wherein the third thin film transistor includes a first gate electrode below the third oxide semiconductor layer and a second gate electrode above the third oxide semiconductor layer, wherein at least part of the third oxide semiconductor layer is provided between a source electrode and a drain electrode, and the second gate electrode overlapping with the third oxide semiconductor layer and the first gate electrode, wherein the third oxide semiconductor layer is formed over the source electrode and the drain electrode, and wherein the second thin film transistor is one of an enhancement type transistor and a depletion type transistor and the third thin film transistor is the other of the enhancement type transistor and the depletion type transistor.