Patent ID: 8097883

Claim:
A thin film transistor comprising: a substrate including a pixel portion and a driver portion; a first semiconductor layer disposed in the pixel portion and having a first surface roughness; a second semiconductor layer disposed in the driver portion and having a second surface roughness larger than the first surface roughness, wherein the first semiconductor layer and the second semiconductor layer are disposed on the same substrate; a first gate electrode disposed to correspond to the first semiconductor layer; a second gate electrode disposed to correspond to the second semiconductor layer; a gate insulating layer disposed between the first and second semiconductor layers and the first and second gate electrodes; first source and drain electrodes electrically connected to source and drain regions of the first semiconductor layer; and second source and drain electrodes electrically connected to source and drain regions of the second semiconductor layer, wherein, a root mean square (RMS) ratio of the first surface roughness to the second surface roughness is 25˜90%, and the first surface roughness is 18-270 Å.