1. Observation and characterization of impact ionization-induced OFF-state breakdown in Schottky-type p-GaN gate HEMTs.
- Author
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Cheng, Yan, Wang, Yuru, Feng, Sirui, Zheng, Zheyang, Chen, Tao, Lyu, Gang, Ng, Yat Hon, and Chen, Kevin J.
- Subjects
TWO-dimensional electron gas ,IMPACT ionization ,MODULATION-doped field-effect transistors ,HOT carriers ,BUFFER layers ,THRESHOLD voltage - Abstract
In this work, the impact ionization-induced OFF-state breakdown is revealed and systematically investigated in 100 V Schottky-type p-GaN gate high-electron-mobility transistors. Impact ionization is found to occur in the peak electric-field region at the source-terminated field-plate edge and is initiated by electrons injected from the source-side two-dimensional electron gas channel through the buffer layer. Hot electrons generated from impact ionization, when being captured by surface traps, could lead to redistribution and peak value reduction of electric-field. Consequently, the sudden rise in the OFF-state leakage current by impact ionization could be self-clamped temporally to avoid catastrophic rupture of the device. The impact ionization is further verified by the increase in dynamic OFF-state leakage current and a negative shift in threshold voltage, both of which result from positively charged holes (generated from impact ionization) drifting toward the gated channel. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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