Performances of Microcrystalline Zinc Tin Oxide Thin-Film Transistors Processed by Spray Pyrolysis

In this work, we report results concerning the performances of thin-film transistors (TFTs) where the channel layer is based on microcrystalline zinc tin oxide (ZTO) processed by spray pyrolysis technique. TFTs made with ~30 nm thick ZTO channel layer deposited at a substrate temperature of 400°C and 300°C exhibited, respectively, a saturation mobility of ~2.9 cm²·V^-1·s^-1 and 1.45 cm²·V^-1·s^-1; VON voltage of ~0.15 V, and 0.2 V; a sub-threshold swing of ~400 mV/dec and 500 mV/dec; ON/OFF ratio at the onset of hard saturation current of ~3.5×10⁵ and 6×10³, for a drain to source voltage of 10 V (close to or below the gate to source voltage). This indicates that the substrate temperature is relevant in determining the devices´ electronic performances.