Patent ID: 7884369

Claim:
A display device comprising: a first gate wiring on an insulating surface; a second gate wiring on the insulating surface, wherein each of the first gate wiring and said second gate wiring comprises: a first conductive layer on the insulating surface; a second conductive layer comprising copper or aluminum on the first conductive layer; and a third conductive layer on the second conductive layer, a gate insulating film over the second gate wiring; a channel forming region and a pair of impurity regions, over the gate insulating film; a connection electrode over the pair of impurity regions, and directly connected to the first gate wiring and one of the pair of impurity regions; and a pixel electrode over the pair of impurity regions, and electrically connected to another one of the pair of impurity regions, wherein a cross-section of each of the first conductive layer, the second conductive layer, and the third conductive layer has a taper shape, and wherein an angle of the taper shape of the second conductive layer is larger than that of the first conductive layer.