High-performance ZnO thin-film transistor fabricated by atomic layer deposition

Abstract

We report the fabrication and characteristics of a ZnO thin-film transistor (TFT) using a 50 nm thick ZnO film as an active layer on an Al2O3 gate dielectric film deposited by atomic layer deposition. Lowering the deposition temperature allowed the control of the carrier concentration of the active channel layer (ZnO film) in the TFT device. The ZnO TFT fabricated at 110 °C exhibited high-performance TFT characteristics including a saturation field-effect mobility of 11.86 cm2 V−1 s−1, an on-to-off current ratio of 3.09 × 107 and a sub-threshold gate-voltage swing of 0.72 V decade−1.