Enhanced Performance and Thermal Stability of a-Si:H TFTs

We report the effect of anneal time on the performance and temperature stability of hydrogenated amorphous silicon (a-Si:H) thin-film-transistors (TFTs). The subthreshold swing and off-current are reduced by a factor of 2.5 and by almost 2 orders of magnitude for 48 h annealed TFTs, respectively, when compared to unannealed TFTs. Furthermore, long annealed TFTs show significant temperature stability when compared to the unannealed TFTs. The subthreshold swing, hysteresis, electron mobility, and off-current are stable even at elevated temperatures. The stability at elevated temperatures and better performance of long annealed TFTs are attributed to improved a-Si: H channel and/or the a-Si: H/insulator interface. (C) 2010 The Electrochemical Society. [DOI: 10.1149/1.3501989] All rights reserved.