Low-Voltage-Driven Flexible InGaZnO Thin-Film Transistor With Small Subthreshold Swing

Abstract

A flexible thin-film transistor (TFT) was made by integrating a high-kappa HfLaO gate dielectric and an amorphous-InGaZnO (a-IGZO) active layer on a polyimide substrate. This flexible HfLaO/a-IGZO TFT exhibits a low threshold voltage of 0.1 V, a small subthreshold swing of 0.18 V/dec, a high maximum saturation mobility of 22.1 cm(2)/V . s, and an acceptable ON/OFF current ratio of 2 x 10(5). The low threshold voltage and small subthreshold swing allow the device to operate at 1.5 V for low-power applications, which should enable significant future progress in energy efficiency.