Patent ID: 7002178

Claim:
A thin film transistor device, comprising: a substrate; a buffer layer on the substrate; an island-shaped active layer on the buffer layer, the island-shaped active layer is formed of polycrystalline silicon and includes first undoped areas, a second lightly doped area, and third highly doped areas; a gate insulation layer on the buffer layer and covering the island-shaped active layer; a dual-gate electrode on the gate insulation layer and including first and second gate electrodes corresponding to the first undoped areas; an interlayer insulator formed on the gate insulation layer and covering the dual-gate electrode; source and drain contact holes penetrating the interlayer insulator and the gate insulation layer to expose the third highly doped areas; a gate contact hole penetrating the interlayer insulator to expose a portion of the dual-gate electrode; a third gate electrode on the interlayer insulator and contacting the exposed portion of the dual-gate electrode through the gate contact hole; and source and drain electrodes formed on the interlayer insulator and contacting the third highly doped areas through the source and drain contact holes.