Patent ID: 8735896

Claim:
A semiconductor device comprising: a substrate; a gate electrode over the substrate; a first gate insulating film over the gate electrode; a first semiconductor layer over the first gate insulating film; a pair of second semiconductor layers over the first semiconductor layer; a pair of third semiconductor layers over the pair of second semiconductor layers; a first conductive layer over a first one of the pair of third semiconductor layers; a second conductive layer over a second one of the pair of third semiconductor layers; and an insulating film over the first conductive layer and the second conductive layer, wherein the gate electrode comprises titanium, wherein the first gate insulating film comprises silicon nitride, wherein the pair of second semiconductor layers comprises microcrystalline silicon, wherein the pair of third semiconductor layers comprises microcrystalline silicon, wherein the insulating film is in contact with the first semiconductor layer between the pair of second semiconductor layers, wherein the pair of third semiconductor layers comprises phosphorus, wherein the pair of second semiconductor layers has conductivity lower than the pair of third semiconductor layers, wherein the first conductive layer and the second conductive layer comprises: a first layer comprising titanium; and a second layer on the first layer, the second layer comprising aluminum, and wherein the insulating film comprises silicon nitride.