Highly Stable, Solution‐Processed Ga‐Doped IZTO Thin Film Transistor by Ar/O₂ Plasma Treatment

The effects of gallium doping into indium–zinc–tin oxide (IZTO) thin film transistors (TFTs) and Ar/O 2 plasma treatment on the performance of a‐IZTO TFT are reported. The Ga doping ratio is varied from 0 to 20%, and it is found that 10% gallium doping in a‐IZTO TFT results in a saturation mobility ( µs at ) of 11.80 cm 2 V −1 s −1 , a threshold voltage ( V th ) of 0.17 V, subthreshold swing (SS) of 94 mV dec −1 , and on/off current ratio ( I on / I off ) of 1.21 × 10 7 . Additionally, the performance of 10% Ga‐doped IZTO TFT can be further improved by Ar/O 2 plasma treatment. It is found that 30 s plasma treatment gives the best TFT performances such as µs at of 30.60 cm 2 V −1 s −1 , V th of 0.12 V, SS of 92 mV dec −1 , and I on / I off ratio of 7.90 × 10 7 . The bias‐stability of 10% Ga‐doped IZTO TFT is also improved by 30 s plasma treatment. The enhancement of the TFT performance appears to be due to the reduction in the oxygen vacancy and OH concentrations.