Patent ID: 8669663

Claim:
A semiconductor device comprising: a semiconductor layer; an insulating layer having a step over the semiconductor layer; a wiring overlapping with the semiconductor layer with the insulating layer interposed therebetween, wherein a side surface of the wiring has a plurality of inclined planes, a first inclined plane has a first angle in a range of 50° to 70° with respect to the insulating layer, a second inclined plane has a second angle in a range of 20° to 60° with respect to the insulating layer, and the first inclined plane is in contact with the insulating layer, wherein a thickness of a first region of the insulating layer that is not overlapped with the wiring is reduced to be less than a thickness of a second region of the insulating layer that is overlapped with the wiring to form the step, wherein the first angle is larger than the second angle, and wherein the wiring is electrically connected to the semiconductor layer through a contact hole formed in the insulating layer.