Abstract In this study, high pressure H2O annealing (HPA) was performed to improve the reliability of low temperature poly-Si thin film transistors (LTPS TFTs) fabricated on a polyimide (PI) substrate. Due to the low heat resistance of the PI substrate, the pressure was high to reduce the temperature of the heat treatment. HPA was performed at 130 °C and 0.3 Mpa in an H2O ambient for 2 h. After HPA treatment, the threshold voltage (VT) shifted to the positive direction from −2.27 V to −1.75 V, and the hysteresis (ΔVT) decreased from 0.67 V to 0.24 V. The density of states (DOS) measurement shows that the interface trap decreased after HPA processing, hence, it is assumed that stability for bias stress has improved. Before and after HPA, the VT shift for negative bias temperature instability (NBTI) stress was 1.19 V and 0.2 V, respectively. After HPA treatment, ΔVT decreased significantly for bias stress. It seems that the decomposed oxygen from H2O diffused to the gate insulator and combined with Si to reduce the oxygen vacancy. The strength of the gate insulator improved after HPA.

中文翻译：

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通过高压 H2O 退火改善 LTPS TFT 的负偏压温度不稳定性

摘要 在这项研究中，进行高压 H2O 退火 (HPA) 以提高在聚酰亚胺 (PI) 衬底上制造的低温多晶硅薄膜晶体管 (LTPS TFT) 的可靠性。由于 PI 基材的耐热性较低，因此压力较高以降低热处理温度。HPA 在 130 °C 和 0.3 Mpa 的 H2O 环境中进行 2 小时。HPA 处理后，阈值电压 (VT) 从 -2.27 V 向正方向移动至 -1.75 V，滞后 (ΔVT) 从 0.67 V 下降至 0.24 V。 态密度 (DOS) 测量表明界面HPA 处理后陷阱减少，因此，假设偏置应力的稳定性有所提高。在 HPA 之前和之后，负偏压温度不稳定性 (NBTI) 应力的 VT 偏移分别为 1.19 V 和 0.2 V。HPA 处理后，ΔVT 显着降低偏置应力。似乎来自 H2O 的分解氧扩散到栅极绝缘体并与 Si 结合以减少氧空位。HPA 后栅极绝缘体的强度有所提高。