Effects of gamma-ray irradiation on polycrystalline silicon thin-film transistors

The effects of gamma-ray irradiation on the performance of polycrystalline silicon thin-film transistors are investigated. After irradiation, the threshold voltage of the TFTs is shifted negatively and well-defined kinks are formed in the subthreshold regions of the transfer characteristics, explained by the turn-on of back channel and sidewall leakage current paths. In the non-irradiated device, the leakage current I-L is controlled by the reverse biased drain junction, while after irradiation IL is limited by the intrinsic resistance of the polysilicon material itself. (C) 2002 Elsevier Science Ltd. All rights reserved.