Zinc tin oxide transistors on flexible substrates

Abstract Flexible transistors were fabricated by sputter deposition of zinc tin oxide (ZTO) onto plasma-enhanced chemical vapor deposited gate dielectrics formed on flexible polyimide substrates with aluminum gate electrodes. Using output characteristics, the contact resistance of Al/ZTO contacts was found to be in the range of 100 kΩ causing significant on-current degradation. ZTO transistors with indium tin oxide (ITO) contacts exhibited high on-currents of 1.5 mA, on/off ratios of 106, subthreshold voltage slopes of 1.6 V/decade, threshold voltages of −8.8 V, and mobilities of 14 cm2 V−1 s−1. Capacitance measurements are shown to be useful for assessing contact resistance.