Research on structural reinforcement of AlGaN/GaN HEMT devices under RF stress

This study investigates the performance and reliability of AlGaN/GaN high electron mobility transistors (HEMTs) under radio frequency (RF) stress through a device-level simulation of a commercial power amplifier. By analyzing the electrical characteristics, breakdown voltage, and RF performance under normal operation and before/after RF stress, we examined the influence of key structural parameters on the device's resistance to RF stress. The parameters studied include the passivation layer thickness, the gate-to-drain to gate-to-source length ratio (Lgd:Lgs), and the buried gate depth. Specifically, an increase in the passivation layer thickness from 0.095 μm to 0.245 μm resulted in a relatively limited improvement in RF stress resistance of 3.45%. In contrast, a variation in Lgd:Lgs from 2:1 to 1:2 and an increase in the buried gate depth from 1 nm to 3 nm led to more pronounced enhancements of 38.3% and 44.4%, respectively. Finally, TCAD simulation results visually illustrate the extent of improvement in RF stress resistance achieved through each structural modification.