Patent ID: 7812348

Claim:
A thin-film transistor comprising: a pair of impurity semiconductor layers with a space therebetween, the pair of impurity semiconductor layers including an impurity element imparting one conductivity type, wherein the pair of impurity semiconductor layers overlap at least partly with a gate electrode with a gate insulating layer therebetween; a pair of second semiconductor layers including an acceptor impurity, wherein the pair of second semiconductor layers is overlapped at least partly with the gate electrode and the pair of impurity semiconductor layers, over the gate insulating layer, is in contact with the gate insulating layer, and is disposed with a space therebetween in a channel length direction; and an amorphous semiconductor layer over the pair of second semiconductor layers, wherein the amorphous semiconductor layer is in contact with the pair of second semiconductor layers and a portion of the gate insulating layer between the pair of second semiconductor layers.