摘要
Water \left(\mathrm{H}_{2} \mathrm{O}\right) is generally considered detrimental to oxide semiconductor devices due to its role in generating trap states. In this work, a controlled in-situ H 2 O treatment using an atomic layer deposition (ALD) system is proposed for IGZO thin-film transistors (TFTs). The optimized treatment results in a negative shift in threshold voltage \left(\mathrm{V}_{\text{TH}}\right) and enhanced on-state current \left(\mathrm{I}_{\text{ON}}\right) , while maintaining stable subthreshold swing (SS) and significantly reducing hysteresis. In addition, the positive bias stress (PBS) stability is improved, with \mathrm{V}_{\text{TH}} shift reduced from 170 mV to 75 mV. These improvements are attributed to the dual role of H 2 O-related species: hydrogen passivates defect states, while hydroxyl (-OH) bonds increase carrier concentration. This work demonstrates that, under controlled conditions, H 2 O can serve as an effective defect engineering tool for high-performance IGZO TFTs.