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

A flexible thin-film transistor (TFT) was made by integrating a high- 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 cm2/V s, and an acceptable on/off current ratio of 2 × 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.