Gate Recess Depth-Dependent Performance Variations in AlGaN/GaN HEMTs Induced by Packaging

Abstract

This study examines the effect of gate recess depth on the electrical and RF performance of AlGaN/GaN high electron mobility transistors (HEMTs) before and after die-attach. Devices with greater recess depths exhibited notably larger improvements in transconductance and RF metrics (f_t, f_max) due to mechanical and thermal stresses induced by packaging, which partially mitigated damage caused by recess etching. However, these recessed devices simultaneously showed substantial increases in gate and drain leakage currents due to activation of interface traps, highlighting the complex trade-off effects introduced by deep recess structures and packaging processes.