The dynamic on-resistance increase during power switching is one of the challenges of GaN-based HEMTs (high-electron-mobility transistors) for power electronic applications. Both the surface traps and buffer traps reduce channel carriers, resulting in decreased operating current during power switching. In this work, we propose a source metal trench toward the buffer region to alleviate channel carriers’ trapping in the buffer region. We compare the dynamic behaviors of the HEMTs with the source trench fabricated within and out of the mesa region. The results indicate less dynamic on-resistance increase at higher drain and gate stress voltages of the device with source trench in the mesa, as compared with the device with source trench fabricated away from mesa, or the one without a trench. We further develop physical models, including multiple current-conducting paths, reduction of buffer traps through source trench, and the re-distribution of the electric field profile, to explain the phenomenon.

中文翻译：

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GaN-On-Si HEMT中的深源金属沟槽以缓解电流崩塌

功率开关过程中动态导通电阻的增加是功率电子应用中基于GaN的HEMT（高电子迁移率晶体管）的挑战之一。表面阱和缓冲阱都减少了沟道载流子，从而导致功率切换期间的工作电流减小。在这项工作中，我们提出了一个向着缓冲区的源极金属沟槽，以减轻沟道载流子在缓冲区中的捕获。我们将HEMT的动态行为与在台面区域内外制造的源极沟槽进行了比较。结果表明，与具有远离台面制造的源极沟槽的器件或不具有沟槽的器件相比，在台面中具有源极沟槽的器件在较高的漏极和栅极应力电压下，动态导通电阻增加的幅度较小。我们进一步开发物理模型，