Zinc tin oxide thin-film transistors via reactive sputtering using a metal target

Abstract

Zinc tin oxide based thin-film transistors are fabricated via reactive magnetron sputtering using a metallic zinc/tin alloy target. The oxygen partial pressure and total sputtering pressure are explored. An oxygen partial pressure and total sputtering pressure of 0.8 and 30mTorr, respectively, are found to be optimal. Devices with a reactively sputtered zinc tin oxide channel layer and channel layer annealing of 500°C exhibit incremental mobilities of ∼32cm2V−1s−1, turn-on voltage of ∼−4V and drain current on-to-off ratios of ∼107. Both direct current and radio frequency magnetron sputtering are explored showing similar characteristics.