Enhancing electrical performance and stability of nanometer-thin ITO transistors via thermally oxidized alumina passivation layer

In this study, we investigated the utilization of alumina (AlOx), formed through the oxidation of thermally evaporated aluminum, as a passivation layer for nanometer-thin indium-tin-oxide (ITO) transistors. The ITO transistors passivated with thermally oxidized AlOx passivation exhibited remarkable electrical properties, with an average field-effect mobility of 241 cm2/Vs, significantly higher than the 40 cm2/Vs observed for devices without the AlOx passivation layer. Moreover, the passivated transistors maintained a high on/off current ratio at 108 level. In addition, the passivated transistors demonstrated improved stability, with a decrease in the threshold voltage (Vth) shift under negative bias stress testing conducted over 3600 seconds. The ITO transistors also displayed better air-ambient stability compared to transistors without the AlOx passivation layer. These results demonstrate the potential application of alumina passivation in nanometer-thin ITO field-effect transistors.