掺杂 InO TFT 在 $400^\circ$C 后处理成型气体退火过程中缺陷动力学与 BTI 行为的实验与建模
Experiments and Modeling of Defect Dynamics and BTI Behavior in Doped InO TFTs during $400^\circ$C Post-Processing Forming Gas Annealing
- Georgia Institute of Technology（佐治亚理工学院）
- University of Granada（格拉纳达大学）
- Applied Materials（应用材料公司）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
本研究结合实验与 DFT-MD 模拟，发现 400°C 成型气体退火中 IWO TFT 缺陷演化由致密化与部分结晶主导，短时退火致 PBTI 退化，延长退火后 PBTI 降至 10.4 mV 并消除扭结，证明阻氢封装可保障 M3D 集成可靠性。
AI中文摘要：
我们研究了单片三维（M3D）集成工艺关键步骤——$400^\circ$C 后处理成型气体退火（FGA）——对氧化物沟道薄膜晶体管（TFT）电性能、可靠性和缺陷演化的影响，将系统实验与基于密度泛函理论（DFT）的液态淬火分子动力学（MD）模拟相结合。采用铟钨氧化物（IWO）TFT 作为模型系统，并用 3 nm Al$_2$O$_3$/3 nm HfO$_2$ 混合薄层封装，该层有效抑制外部氢侵入。我们揭示了 FGA 过程中器件行为的非单调演化，其由初始致密化及随后的部分结晶所主导。短时 FGA（10 分钟）诱导沟道致密化并形成浅层、离域缺陷态，导致显著的正偏压温度不稳定性（PBTI）退化以及特征转移曲线“扭结”的出现。随着退火时间延长（>40 分钟），氧化物沟道发生部分结晶，将氢稳定在深层、局域缺陷态中，抑制氢迁移率并恢复器件可靠性。结果，PBTI 偏移在 2000 秒应力后降至 10.4 mV，同时转移曲线扭结完全消除。这些发现提供了高温后处理 FGA 期间氢-缺陷相互作用的机理理解，并证明适当的阻氢封装能够在不影响电性能或可靠性的前提下实现氧化物沟道 TFT 集成。
英文摘要：
We investigate the impact of a monolithic three-dimensional (M3D) integration process-critical $400^\circ$C post-processing forming gas anneal (FGA) on the electrical performance, reliability, and defect evolution of oxide-channel thin-film transistors (TFTs), combining systematic experiments with density-functional-theory (DFT)-based liquid-quench molecular-dynamics (MD) simulations. Indium tungsten oxide (IWO) TFTs are employed as a model system and encapsulated with a thin 3 nm Al$_2$O$_3$ / 3 nm HfO$_2$ hybrid layer that effectively suppresses external hydrogen ingress. We reveal a non-monotonic evolution of device behavior during FGA, governed by initial densification followed by partial crystallization. Short-duration FGA (10 min) induces channel densification and the formation of shallow, delocalized defect states, leading to pronounced positive bias temperature instability (PBTI) degradation and the emergence of a characteristic transfer-curve "kink." With prolonged annealing (>40 min), partial crystallization of the oxide channel occurs, stabilizing hydrogen in deep, localized defect states, suppressing hydrogen mobility, and restoring device reliability. As a result, the PBTI shift is reduced to 10.4 mV after 2000 seconds of stress, accompanied by complete elimination of the transfer-curve kink. These findings provide a mechanistic understanding of hydrogen-defect interactions during high-temperature post-processing FGA and demonstrate that appropriate hydrogen-blocking encapsulation enables oxide-channel TFT integration without compromising electrical performance or reliability.
