Resolution of amorphous silicon thin-film transistor instability mechanisms using ambipolar transistors

Abstract

Bias stress measurements on amorphous silicon-silicon nitride ambipolar thin-film transistors give clear evidence for the co-existence of two distinct instability mechanisms: the metastable creation of states in the a-Si:H layer and charge trapping in the a-SiN:H layer. The creation of metastable states in the a-Si:H is found to dominate at low positive bias, while charge trapping in the nitride dominates at larger positive bias and negative bias.