Direct Observation of Gate Leakage Paths in AlGaN/GaN High Electron Mobility Transistors by Electron Beam-Induced Current

作者：Chen, Lixiang; Ma, Xiaohua^*; Zhu, Jiejie; Hou, Bin; Zhu, Qing; Zhang, Meng; Yang, Ling; Yin, Jun; Wu, Jiafen; Hao, Yue

来源：IEEE Transactions on Device and Materials Reliability, 2018, 18(3): 359-363.

DOI：10.1109/TDMR.2018.2847664

• AlGaN/GaN
• high-electron-mobility transistors (HEMTs)
• electron beam-induced current (EBIC)
• gate leakage

In this study, the electron beam-induced current technique was used to investigate the spatial distribution of gate leakage paths in AlGaN/GaN high electron mobility transistors. The mesa-type devices exhibited three leakage paths: the mesa edge leakage, the sidewall leakage, and the isolation leakage. In mesa-isolated devices with a SiN passivation layer, the dominant leakage paths were through the SiN/GaN interface as a result of the imperfections at the SiN/semiconductor interface. The mesa sidewall leakage in a passivated device gradually decreased from the gate to the source/drain along the mesa edge. This was correlated with the diffusion length and the distance of the electron beam from the gate. In the device without a SiN passivation layer, the major leakage path was found to be through the mesa edge under the gate metal, which was induced by the gate-channel overlap at the mesa edge.

• 出版日期2018-9
• 单位西安电子科技大学