Low-Cost and High-Performance, Back-Channel Etched InGaZnO Thin Film Transistors by Spray Pyrolysis

We demonstrate the high performance, crystalline InGaZnO (c-IGZO) TFT using spray pyrolysis by varying the substrate temperature from 375 °C to 450 °C. A high quality c-IGZO thin film can be formed at a growth temperature of 425°C. The c-IGZO TFT with back-channel structure exhibits the high saturation mobility of 60.17 cm2/Vs, low subthreshold swing of 90 mV/dec, and high on/off drain current ratio of
$\sim 10^{{9}}$
. The c-IGZO TFT exhibits the excellent stability under positive bias temperature stress with threshold voltage shift less than 0.1V. The remarkable performance of c-IGZO TFT by spray pyrolysis is attributed to the formation of dense c-IGZO structure. Therefore, the c-IGZO TFTs by spray pyrolysis have great potential to be employed in low-cost display manufacturing.