%A Ya-Wen Zhao(赵亚文), Liu-An Li(李柳暗), Tao-Tao Que(阙陶陶), Qiu-Ling Qiu(丘秋凌), Liang He(何亮), Zhen-Xing Liu(刘振兴), Jin-Wei Zhang(张津玮), Qian-Shu Wu(吴千树), Jia Chen(陈佳), Zhi-Sheng Wu(吴志盛), Yang Liu(刘扬) %T Experimental evaluation of interface states during time-dependent dielectric breakdown of GaN-based MIS-HEMTs with LPCVD-SiNx gate dielectric %0 Journal Article %D 2020 %J Chin. Phys. B %R 10.1088/1674-1056/ab8895 %P 67203-067203 %V 29 %N 6 %U {https://cpb.iphy.ac.cn/CN/abstract/article_122565.shtml} %8 2020-06-05 %X 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.