Investigation of LaAlO 3 /ZrO 2 / a ‐InGaZnO thin‐film transistors using atmospheric pressure plasma jet

Amorphous indium–gallium–zinc‐oxide thin‐film transistors ( a ‐IGZO‐TFTs) with the LaAlO 3 /ZrO 2 gate dielectric stack employing a novel atmospheric pressure plasma jet process that results in small subthreshold swing and low threshold voltage are proposed and fabricated. The influence of post‐deposition annealing (PDA) temperature on LaAlO 3 /ZrO 2 gate dielectric stack and device performance was investigated. The equivalent oxide thickness of the LaAlO 3 /ZrO 2 dielectric stack decreases from 11.5 nm without annealing to 7 nm after a 500°C annealing was applied. The LaAlO 3 /ZrO 2 / a ‐InGaZnO TFT with a 500°C annealing exhibits a small subthreshold swing of 77 mV·dec −1 , a high field‐effect mobility of 9 cm 2 ·V −1 ·s −1 and an excellent current ratio of 1.8 × 10 7 , which could be attributed to the improved gate dielectric quality by the PDA. The LaAlO 3 /ZrO 2 / a ‐InGaZnO TFTs with excellent gate control ability allow the device to operate at a low operating voltage with low power consumption.