Single-Event Hardened P-GaN Gate HEMT With Schottky Source Structure

In this work, we report a p-GaN gate high-electron-mobility transistor (HEMT) with Schottky source (SS-HEMT), which can effectively enhance the single-event hardness under heavy-ion irradiation. The SS deep into the GaN channel layer can facilitate the extraction of the radiation-induced non-equilibrium holes without any energy barrier, thereby boosting the single-event burnout (SEB) voltage to ~525 V from ~450 V in the conventional HEMT (C-HEMT) under a linear energy transfer (LET) of 38 MeV$\cdot$cm2/mg. The SS-HEMT, enabling enhanced SEB hardness, can still maintain comparable forward/reverse conduction, reverse blocking, and parasitic capacitance characteristics with the C-HEMT. With the experimentally extracted Schottky barrier height (SBH) of ~0.79eV at the SS/GaN interface, TCAD simulations have been conducted to investigate the radiation-induced carrier distribution to reveal the underlying mechanism for SEB hardening by SS. The influences of SBH, applied bias to SS, depth of SS, and the distance between SS and ohmic source on the hole extraction have also been comprehensively investigated by single-event effect (SEE) simulations. The SEB hardening technology and the underlying mechanism analysis for non-equilibrium hole extraction in this work are valuable toward the development of highly robust GaN devices for aerospace applications.