Patent ID: 8421135

Claim:
A display device comprising: a substrate; a source wiring line over the substrate; a gate electrode over the substrate; a first insulating film formed over the source wiring line and the gate electrode, the first insulating film having a first contact hole over the source wiring line; a first amorphous semiconductor film containing a channel forming region formed over the first insulating film; a second semiconductor film and a third semiconductor film both containing an impurity element formed over the first amorphous semiconductor film; a metal wiring line formed over the second semiconductor film, wherein the metal wiring line is in electrical contact with the source wiring line and the second semiconductor film; a gate wiring line over the first insulating film and extending across the source wiring line, the gate wiring line being electrically connected to the gate electrode; a second insulating film formed over the source wiring line and the second and third semiconductor films, the second insulating film having a first contact hole over the third semiconductor film and a second contact hole over the second semiconductor film; and a pixel electrode formed over the second insulating film and electrically connected to the third semiconductor film through the first contact hole of the second insulating film, wherein the metal wiring line is in electrical contact with the source wiring line through the first contact hole of the first insulating film, and wherein the metal wiring line is in electrical contact with the second semiconductor film through the second contact hole of the second insulating film.