Patent ID: 7592628

Claim:
A system for displaying images, comprising: a thin film transistor device, comprising: a substrate comprising a driving circuit region and a pixel region; first and second active layers disposed on the substrate in the driving circuit region and in the pixel region, respectively, wherein each of the first and second active layers comprises a channel region, a source/drain region and a lightly doped region formed therebetween, wherein combined length of the channel region and the lightly doped region of the first active layer is different from combined length of the channel region and the lightly doped region of the second active layer; and two gate structures disposed on the first and second active layers, respectively, wherein each gate structure comprises a stacked first and second gate dielectric layers and a gate layer having a gate length, and the second gate dielectric layer has a length shorter than that of the first gate dielectric layer but longer than the gate length of the gate layer; wherein the lightly doped region of the first active layer has a length different from that of the second active layer.