P‐9: Improved Electrical Stability of Double‐Gate a‐IGZO TFTs

The electrical stability of double-gate (DG) and single-gate (SG) amorphous indium-gallium-zinc oxide (a-IGZO) TFTs is investigated and compared. The SG device shows an abnormal negative shift in Vth accompanying with deterioration in SS under PBS, which is not observed in DG device or SG device stressed in vacuum. Moreover, the SG device exhibits a much larger negative Vth shift than DG device and SG device stressed in vacuum. The improved electrical stability of DG device comes from not only the lowered vertical electric field but also more effective moisture resistance due to the shield of DG electrodes.