Thin film transistors having source wiring and terminal portion made of the same material as the gate electrodes

A semiconductor device comprising:

• a pixel portion comprising at least one first n-channel thin film transistor formed over a substrate;
• a driving circuit comprising at least second and third n-channel thin film transistors formed over the substrate, each of the first, second and third n-channel thin film transistors comprising:
• a semiconductor layer formed on an insulating surface over the substrate;
• an insulating film formed on the semiconductor layer;
• and
• a gate electrode formed over the semiconductor layer wit h the insulating film interposed therebetween;
• a source wiring provided in the pixel portion and comprising a same material as the gate electrode;
• and
• a terminal portion comprising the same material as the gate electrode.

A semiconductor device comprising:

• a pixel portion comprising at least one first n-channel thin film transistor formed over a substrate;
• a driving circuit comprising at least second and third n-channel thin film transistors formed over the substrate, each of the first, second and third n-channel thin film transistors comprising:
• a semiconductor layer formed on an insulating surface over the substrate;
• an insulating film formed on the semiconductor layer;
• and
• a gate electrode formed over the semiconductor layer wit h the insulating film interposed therebetween,
• a source wiring provided in the pixel portion;
• and
• a terminal portion formed over said substrate,
• wherein said source wiring and said terminal portion are formed b y patterning a same conductive film as said gate electrode.

A semiconductor device comprising:

• a pixel portion comprising at least one first n-channel thin film transistor formed over a substrate;
• a driving circuit comprising at least second and third n-channel thin film transistors formed over the substrate, each of the first, second and third n-channel thin film transistors comprising:
• a semiconductor layer formed on an insulating surface over the substrate;
• an insulating film formed on the semiconductor layer;
• and
• a gate electrode formed over the semiconductor layer wit h the insulating film interposed therebetween,
• a source wiring provided in the pixel portion;
• an interlayer insulating film covering at least the first n-channel thin film transistor and the source wiring;
• a conductive film formed on the interlayer insulating film wherein said source wiring is electrically connected to an impurity region of the first n-channel thin film transistor through said conductive film;
• and
• a terminal portion formed over said substrate,
• wherein said source wiring and said terminal portion are formed by patterning a same conductive film as said gate electrode.