Improved stability of deuterated amorphous silicon thin film transistors

To improve the bias-induced degradation in hydrogenated amorphous silicon thin film transistor, the hydrogen in the amorphous silicon film should be replaced by deuterium. The stability of deuterated amorphous silicon thin film transistors, i.e., the shifts of threshold voltage and subthreshold swing, is indeed improved compared to that of the hydrogenated ones. This result is consistent with the improvement of the light-induced degradation in deuterated amorphous silicon films and this improvement can be explained by the efficient coupling between the Si-D wagging mode and the amorphous silicon phonon mode. (C) 1999 American Institute of Physics. [S0021-8979(99)04301- 7].