Stability of hot-wire deposited amorphous-silicon thin-film transistors

For the first time hydrogenated amorphous silicon, a-Si:H, deposited with the hot-wire technique is incorporated in thin-film transistors (TFTs). 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 gate voltage stress, virtually no change in any of these TFT parameters is observed. Conventional state-of-the-art TFTs deposited in a 13.56 MHz 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 layer needs further optimization. After gate voltage stress, the TFTs containing hot-wire a-Si:H have superior quality with respect to the threshold voltage. (C) 1996 American Institute of Physics.