Amorphous silicon thin-film transistors and arrays fabricated by jet printing

Phase-change wax-based printed masks, in place of conventional photolithography, were used to fabricate hydrogenated amorphous silicon thin-film transistors (TFTs). Wax-mask features with a minimum feature size of similar to20 mum were achieved using an acoustic-ink-printing process. Both discrete and matrix addressing structured bottom-gate TFTs with source-drain contacts overlapping the channel were created using a four-mask process. The TFTs had current-voltage characteristics comparable to photolithographically patterned devices, with mobility of 0.6-0.9 cm(2)/V s, threshold voltage of 2-3 V, and on/off ratios exceeding 10(7) for devices with channel lengths below 50 mum. (C) 2002 American Institute of Physics.