Experimental evaluation of interface states during time-dependent dielectric breakdown of GaN-based MIS-HEMTs with LPCVD-SiNx gate dielectric
Experimental evaluation of interface states during time-dependent dielectric breakdown of GaN-based MIS-HEMTs with LPCVD-SiNx gate dielectric
复制标题
具有 LPCVD-SiNx 栅极电介质的 GaN 基 MIS-HEMT 随时间变化的电介质击穿过程中界面态的实验评估
DOI：
10.1088/1674-1056/ab8895
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Yang Liu
中科院分区：
文献类型：
--
作者：
Yawen Zhao;Liuan Li;Taotao Que;Qiuling Qiu;Liang He;Zhenxing Liu;Jinwei Zhang;Qianshu Wu;Jia Chen;Zhisheng Wu;Yang Liu
实验研究了GaN MISHEMTs在时间相关介质击穿(TDDB)过程中的界面态密度。在较高的正向栅压下，SiNx/AlGaN界面和SiNx体区都产生了新的陷阱，导致了电压漂移和电压滞后的增加。随着应力持续时间的延长，SiNx介质中产生的缺陷密度占主导地位，导致栅漏电流急剧增加，导致灾难性的失效。在紫外光照射下恢复后，阈值电压的负移(与新鲜的相比)证实了正电荷在SiNx/AlGaN界面和/或在SiNx体内的积累，这可能归因于长期应力后的断键。这些结果从实验上证实了缺陷在GaN基MIS-HEMT的TDDB中的作用。
We experimentally evaluated the interface state density of GaN MIS-HEMTs during time-dependent dielectric breakdown (TDDB). Under a high forward gate bias stress, newly increased traps generate both at the SiNx/AlGaN interface and the SiNx bulk, resulting in the voltage shift and the increase of the voltage hysteresis. When prolonging the stress duration, the defects density generated in the SiNx dielectric becomes dominating, which drastically increases the gate leakage current and causes the catastrophic failure. After recovery by UV light illumination, the negative shift in threshold voltage (compared with the fresh one) confirms the accumulation of positive charge at the SiNx/AlGaN interface and/or in SiNx bulk, which is possibly ascribed to the broken bonds after long-term stress. These results experimentally confirm the role of defects in the TDDB of GaN-based MIS-HEMTs.