In situ interface engineering enabled high-performance InSnO thin-film transistor incorporating ultrathin Y2O3 layer

Oxide thin-film transistors (TFTs) suffer from negative bias illumination stress (NBIS) instability, which severely limits their application in flat panel displays. In this study, an ultrathin Y2O3 layer is deposited on top of a 6-nm-thick indium tin yttrium oxide channel layer using an in situ sputtering process. This modification to the back-channel layer demonstrates remarkable improvement in stability. The passivated devices exhibit a high field-effect mobility of 49.7 cm2/V s, an outstanding current on/off ratio of 107, and a threshold voltage (VTH) of −0.9 V. Moreover, the VTH shift under NBIS is significantly reduced from −9.9 to −2.8 V. The passivated devices demonstrating excellent stability can be attributed to the dense Y2O3 layer, which effectively prevents the influence of moisture and oxygen from the ambient environment. And the diffusion of yttrium ions from the Y2O3 layer into the channel layer passivates defects within the channel. This work provides a promising pathway for high-performance oxide TFTs.