High-performance flexible zinc tin oxide field-effect transistors

Flexible transistors were fabricated by sputter deposition of zinc tin oxide (ZTO) onto plasma-enhanced chemical vapor deposition gate dielectrics formed on flexible polyimide substrates with a blanket aluminum gate electrode. The flexible transistors exhibited high on-currents of 1 mA , on/off ratios of 10 6 , subthreshold voltage slopes of 1.6 V /decade, turn-on voltages of − 17 V , and mobilities of 14 cm 2 V − 1 s − 1 . Capacitance measurements indicate that the threshold voltage and subthreshold slope are primarily influenced by residual doping in the ZTO rather than by defects at the semiconductor/dielectric interface, and are useful for assessing contact resistance.