In this article, we investigated the bimodal behavior in the Weibull distribution of time to breakdown during time-dependent dielectric breakdown (TDDB) measurement in GaN metal–insulator–semiconductor high electron mobility transistors (MIS-HEMTs) with Si3N4 gate insulator. We propose that the gate leakage current is a mixture mechanism of Poole–Frenkel (PF) emission and Fower–Nordheim (FN) tunneling current. The dominant mechanism of devices could shift from PF emission to FN tunneling when the stress bias is above a certain value, which is related to the properties of traps in the gate dielectric. The evolution of the leakage mechanism with stress bias leads to the deviation of the Weibull slope from the original one at low stress bias, where PF emission is the dominant one.

中文翻译：

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GaN MIS-HEMT 中随时间变化的介电击穿的偏置相关传导引起的双峰威布尔分布


在本文中，我们研究了具有 Si3N4 栅极绝缘体的 GaN 金属-绝缘体-半导体高电子迁移率晶体管 (MIS-HEMT) 的随时间介电击穿 (TDDB) 测量过程中击穿时间威布尔分布的双峰行为。我们提出栅极漏电流是普尔-弗兰克尔（PF）发射和福尔-诺德海姆（FN）隧道电流的混合机制。当应力偏置高于一定值时，器件的主导机制可能从 PF 发射转变为 FN 隧道效应，这与栅极电介质中陷阱的特性有关。泄漏机制随应力偏差的演化导致威布尔斜率在低应力偏差下偏离原始斜率，其中 PF 发射占主导地位。