This experimental study reports a systematic investigation of Safe Operating Area (SOA) limits in AlGaN/GaN HEMT using sub- $\mu \text{s}$ pulse characterization. During stress, on-the fly Raman and CV characterization is done to probe mechanical strain evolution and the resultant defect/ trap generation across HEMT. Role of carrier trapping induced electric field shift and associated piezoelectric strain in SOA degradation is investigated. SOA is reported to recovery under sub-bandgap UV exposure. Impact of gate recess depth on SOA boundary is discovered and its related physics is unveiled. Post failure analysis done using cross-sectional SEM, EDX and HR-TEM corroborates well with the failure physics proposed in this work.

中文翻译：

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陷阱辅助和应力诱导的 AlGaN/GaN HEMT 的安全工作区域限制

该实验研究报告了使用亚 $\mu\text{s}$ 脉冲表征对 AlGaN/GaN HEMT 中的安全工作区 (SOA) 限制进行的系统调查。在应力期间，进行动态拉曼和 CV 表征以探测机械应变演变以及 HEMT 上由此产生的缺陷/陷阱生成。研究了载流子俘获感应电场位移和相关压电应变在 SOA 退化中的作用。据报道，SOA 在亚带隙紫外线照射下会恢复。发现了栅极凹槽深度对 SOA 边界的影响，并揭示了其相关物理原理。使用横截面 SEM、EDX 和 HR-TEM 进行的失效后分析很好地证实了这项工作中提出的失效物理学。