56‐1: High Stability PEALD‐InGaZnO Thin Film Transistors Realized by Thickness Optimization and Intercalation of Al2O3 Passivation Layers

This work demonstrates an effective strategy for improving the electrical performance and positive bias temperature stability (PBTS) of indium gallium zinc oxide (IGZO) thin‐film transistors (TFTs) through synergistic optimization of the IGZO active layer thickness and the integration of an aluminum oxide (Al₂O₃) passivation interlayer. By systematically adjusting the IGZO thickness, a balance between PBTS and threshold voltage (VTH) was achieved. Furthermore, the introduction of an Al₂O₃ interlayer between the IGZO and passivation interfaces significantly enhanced device PBTS under prolonged bias stress. Comprehensive electrical characterizations confirmed that the optimized TFTs exhibited superior performance, including a field‐effect mobility (μ) of 16.7 cm²/V·s, a VTH of 0.4 V and a subthreshold swing (SS) of 72 mV/dec. More importantly, the optimized device exhibits high stability with a VTH drift of only 16.1 mV after 10,000 seconds of bias at 125°C. These results highlight the critical impact of thickness optimization and interface engineering on achieving reliable IGZO TFTs for next‐generation flexible electronics and high‐resolution displays.