SUPPRESSION OF LEAKAGE CURRENT IN N-CHANNEL POLYSILICON THIN-FILM TRANSISTORS USING NH3 ANNEALING

The effect of NH3 annealing on polysilicon thin-film transistors (poly -Si TFT's) is investigated. Substantial reduction of the off-state lea kage current in self-aligned n-channel poly-Si TFT's is achieved upon NH3 annealing without degradation of on-state characteristics. NH3 ann ealing is believed to generate positive fixed charges in the gate oxid e near the source and drain junction during NH3 annealing. These posit ive fixed oxide charges reduce the electric field in the drain junctio n, resulting in the reduction of the leakage current. NH3 annealing ca n be applied effectively to fabricate high-performance self-aligned po ly-Si TFT's.