Performance Enhancement of Indium Zinc Oxide Thin-Film Transistors Through Process Optimizations

The device performance of indium zinc oxide (IZO) thin-film transistors (TFTs) is optimized through process optimizations. By jointly adjusting the annealing condition, the channel thickness and the sputtering atmosphere, the roughness and oxygen vacancies (Vos) are precisely regulated. The optimized IZO TFTs can achieve the highest field effect mobility of ~71.8 cm2/Vs with a threshold voltage of ~-0.6 V. Reliability of IZO TFTs under positive/negative bias stress is also examined. The interface quality and the Vo are two key factors influencing the device performance and reliability, confirmed by X-ray photoelectron spectroscopy and atomic force microscopy analysis.