[15a-PB2-1~16] 13.7 Compound and power devices, process technology and characterization

English Presentation

[15a-PB2-11] Simulation Study on Damage Mechanism of GaN HEMT under High Power Microwave Stress

〇(M2)Chen Xingda^1,2, Yu Chenghao², Masayuki Yamamoto¹, Guo Haomin², Gong Teng^1,2 (1.University of Yamanashi, 2.Hangzhou Dianzi University)

Keywords:

GaN HEMT,High Power Microwave,Thermal Stress

AlGaN/GaN HEMTs are vulnerable to High Power Microwave (HPM) pulses, where the failure involves Electro-Thermal-Mechanical coupling. This work investigates the transient damage mechanism using multiphysics simulations. We used Sentaurus TCAD to calculate power dissipation under HPM stress and mapped it to COMSOL to solve for lattice temperature and thermal stress. Results indicate that HPM energy deposition triggers severe self-heating, forming a localized "hotspot" at the drain-side gate edge. The von Mises stress evolution strictly follows the temperature rise, confirming that thermal expansion is the primary driver of mechanical stress. To mitigate this, a source-connected Field Plate (FP) structure is analyzed. The FP effectively suppresses electric field crowding and spreads heat flux, significantly reducing peak thermal stress and enhancing device survivability.