Patent ID: 7486344

Claim:
A liquid crystal display device comprising: a semiconductor layer formed on an insulating surface, said semiconductor layer having a channel forming region, an LDD region contacting said channel forming region, and a source region and a drain region; a gate insulating film formed over said semiconductor layer; a first gate electrode comprising a first conductive film over said gate insulating film; a first wiring formed over said gate insulating film; a second gate electrode comprising a second conductive film over said first gate electrode; a second wiring formed over said first wiring; a first interlayer insulating film formed over said first gate electrode, said first wiring, said second gate electrode and said second wiring; a second interlayer insulating film formed over said first interlayer insulating film; a third wiring formed over said second interlayer insulating film and in contact with said first interlayer insulating film through a contact hole formed in said second interlayer insulating film; wherein a width of said first conductive film in a longitudinal direction of said channel forming region is larger than that of said second conductive film; wherein said channel forming region overlaps said second conductive film with said gate insulating film interposed therebetween; wherein said LDD region overlaps said first conductive film with said gate insulating film interposed therebetween, and wherein said third wiring overlaps said second wiring with said first interlayer insulating film interposed therebetween in said contact hole.