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

Abstract

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