Patent ID: 7993993

Claim:
A method for manufacturing a display device comprising: forming a base layer comprising a metal material over a substrate; forming a gate electrode over a first portion of the base layer; insulating a second portion of the base layer; forming a gate insulating film over the gate electrode and the second portion of the base layer, the gate insulating film comprising a plurality of insulating layers; forming a first semiconductor layer over the gate insulating film, the first semiconductor layer comprising a microcrystalline semiconductor; forming a second semiconductor layer over the first semiconductor layer; etching the first semiconductor layer and the second semiconductor layer, thereby forming a semiconductor island and an impurity region; forming source and drain wiring layers over the impurity region; and etching the impurity region using the source and drain wiring layers as masks, thereby forming source and drain regions, wherein the second portion of the base layer is a portion of the base layer where the gate electrode is not overlapping the base layer, and wherein the second portion of the base layer is in contact with the first portion of the base layer.