Enhanced Performance and Stability of Atomic Layer Deposited In₂O₃ Transistors With Multi-Function Cation-Doped ZnSnO Layers

Ultrathin films of In ₂ O ₃ have demonstrated high transistor mobility yet exhibit vulnerability to stability degradation under bias stress. Here, we engineered ultrathin In ₂ O ₃ films via atomic layer deposition, complemented with a cation-doped ZnSnO semiconductor layer for comprehensive passivation of intrinsic and surface imperfections. The resulting thin-film transistors with HfO ₂ dielectric layer show the improved mobility as 81.5 cm ² V ^-1 s ^-1 and the reversed subthreshold slope value down to 77.1 mV/decade. Under positive or negative gate bias stress (or with illumination), the threshold shift is improved to be -0.14 or -0.26 V (or -0.32 V), respectively. Combined electrical and photoelectrical spectral analysis indicates a robust protection of charge carriers by the multi-functional cation-doped back channel layer, which effectively diminishes defect-mediated scattering, shields against external environmental factors, and facilitates the recombination of excess photo-induced carriers.