Influence of Mg doping level at the initial growth stage on the gate reliability of p-GaN gate HEMTs
Influence of Mg doping level at the initial growth stage on the gate reliability of p-GaN gate HEMTs
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生长初期Mg掺杂水平对p-GaN栅极HEMT栅极可靠性的影响
DOI：
10.1088/1361-6463/ac761b
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发表时间：
2022-06
期刊：
影响因子：
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通讯作者：
Hui Yang
中科院分区：
文献类型：
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作者：
Yijin Guo;Haodong Wang;Xin Chen;Hongwei Gao;Fangqing Li;Yaozong Zhong;Yu Zhou;Qian Li;Wenbo Li;Qian Sun;Hui Yang
本文研究了p型GaN高电子迁移率晶体管（HEMT）的栅极可靠性与p型GaN层生长初期Mg掺杂水平的关系。分析比较了Mg掺杂浓度相对较低和较高的p-GaN栅常关型HEMT器件在制作态、正向阶跃应力、反向阶跃应力和长期反向应力下的性能。结果表明，Mg的过掺杂会使p-GaN/AlGaN/GaN结构的PIN二极管性能下降，从而影响p-GaN栅的可靠性。由于Mg过掺杂引起的高密度缺陷作为明显的类受主陷阱，在负应力作用下，漏电流减小，阈值电压不稳定，栅漏增大。通过对不同Mg浓度下p-GaN栅性能的详细研究，为实现p-GaN栅HEMT的高栅可靠性提供了更深入的理解。
This letter has studied the gate reliability of p-GaN high electron mobility transistors (HEMTs) influenced by the Mg doping level at the initial growth stage of p-GaN layer. Normally-off HEMTs with p-GaN gate fabricated with relatively low and high Mg doping concentration have been analyzed and compared based on their performances at various statuses of as-fabricated, forward step-stressed, reverse step-stressed and long-term reverse stressed. It reveals that Mg over-doping has a detrimental effect on the p-GaN gate reliability through degrading the PIN diode formed by p-GaN/AlGaN/GaN structure. Severe drain current reduction, threshold voltage instability and gate leakage increase have been observed after being negatively stressed due to the high-density defects acting as apparent acceptor-like traps induced by Mg over-doping. The detailed studies on the p-GaN gate performance with various Mg concentrations give a greater depth of understanding to realize high gate reliability of p-GaN gate HEMTs.