Comparative Analysis of Carrier Extraction Related Failure Mechanisms in P-GaN HEMTs Under Single-Event Burnouts

This article discusses the carrier extraction related failure mechanisms in p-GaN gate HEMTs under single-event burnout (SEB) through a comparative analysis based on 181Ta<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><roman>31</roman>+</sup> ion radiation experiments and TCAD simulations. The roles of carrier extraction paths are isolated and examined by introducing potential barriers at the gate (HB-HEMTs), substrate (SF-HEMTs), and drain electrodes (SD-HEMTs), respectively. Distinct SEB characteristics are identified by experiments and <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">I</i>–<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">V</i>-temperature measurements, while the specific failure mechanisms are confirmed by single-event simulations with avalanche and temperature models. HB-HEMTs show a breakdown of the metal/p-GaN gate Schottky diode, while p-GaN/AlGaN diode can still function on account of the carrier extraction through the gate. SF-HEMTs have increased <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">I</i><sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><roman>DS</roman></sub> leakage due to the formation of a back channel when the substrate is floating. SD-HEMTs exhibit more significant damage to Schottky drain contact than gate stacks due to the accumulation of carriers around the drain. These findings emphasize the critical impact of gate, substrate, and drain engineering on SEB resistance and can provide practical guidance in designing p-GaN HEMTs with improved radiation tolerance.