STABILITY OF HOT-WIRE DEPOSITED AMORPHOUS-SILICON THIN-FILM TRANSISTORS

For the first time hydrogenated amorphous silicon, a-Si:H, deposited w ith the hot-wire technique is incorporated in thin-film transistors (T FTs). Amorphous silicon was deposited at a rate of 20 Angstrom/s. TFTs with a switching ratio of 10(5), a threshold voltage of 16.9 V, and a field-effect mobility mu(s) of 0.001 cm(2)/V s are obtained. Upon gat e voltage stress, virtually no change in any of these TFT parameters i s observed. Conventional state-of-the-art TFTs deposited in a 13.56 MH z glow discharge showed a threshold voltage shift of more than +12 V. The interface between the gate dielectric and the hot-wire a-Si:H laye r needs further optimization. After gate voltage stress, the TFTs cont aining hot-wire a-Si:H have superior quality with respect to the thres hold voltage. (C) 1996 American Institute of Physics.