Enhanced stability in InSnO transistors via ultrathin in-situ AlOx passivation.

[Display omitted] • The effect of in-situ AlOx passivation on the stability of InSnO transistors has been investigated. • The in-situ AlOx-passivated InSnO transistors demonstrated satisfactory electrical performance. • For the in-situ AlOx-passivated InSnO transistors, the total trap density is notably decreased. • The NBS, PBS and low-frequency noise of InSnO transistors are significantly improved. In this study, we present the impact of an ultrathin in-situ AlO x passivation layer on the electrical performance and stability of InSnO (ITO) transistors. Devices incorporating an ultrathin (∼2 nm) AlO x passivation layer demonstrate satisfactory electrical performance and stability, characterized by a decent field-effect mobility, enhancement mode operation, notably reduced subthreshold swing, negligible hysteresis, and, notably, a significantly reduced threshold voltage shift under negative bias stress (NBS) and positive bias stress (PBS), respectively. The total trap density (N tot), extracted through the sub-threshold slope, and the trap density (N t), measured using low-frequency noise (LFN) for the AlO x -passivated ITO transistors, are significantly decreased. Those improvements can be attributed to the suppression of oxygen vacancy formation during the reactively-sputtered AlO x and subsequent annealing processes, as demonstrated by comparing the in-depth X-ray photoelectron spectroscopy (XPS) results of the AlO x -passivated and un-passivated ITO films. These results underscore the potential of in-situ reactively-sputtered ultrathin AlO x passivation layers to enhance the stability of thin-film transistors with In-rich channels. [ABSTRACT FROM AUTHOR]