2025/12/17 by Zixin Zhen, Hui Feng, Tianlong Zhao +1
Physics and Astronomy · Engineering · #GaN-based semiconductor devices and materials #Pulsed Power Technology Applications #Silicon Carbide Semiconductor Technologies
paper · doi:10.1109/ted.2025.3641093
This article reports a comprehensive investigation into the failure behavior and underlying mechanisms of a gallium nitride (GaN)-based low-noise amplifier (LNA) induced by high-power microwave (HPM) pulses. A dual-layer failure analysis framework (spanning system and device levels) is proposed to address a critical gap in existing literature: most studies focus on individual GaN high-electron-mobility transistors (HEMTs) rather than GaN-integrated LNAs under high-power electromagnetic stress. Moreover, the existing research progress on LNA reliability under HPM injection conditions is mostly about gallium arsenide (GaAs)-based LNA, such as GaAs heterojunction bipolar transistor (HBT) LNA. First, a custom-designed test system was employed to monitor the electrical performance of the GaN LNA while systematically stepped HPM pulses were injected, enabling the determination of the failure threshold. Second, the failure mechanism of the entire LNA was analyzed at the system level, and the primary failure cause of key components was identified. Obvious damage morphology was detected on one of the first-stage GaN HEMTs and a nearby resistor. Microscopic morphological analysis revealed that the GaN HEMT first undergoes breakdown, followed by a global current increase in the LNA, and ultimately the melting of the resistor—thus clarifying the cascading failure path: from HEMT breakdown to overall current rise, and finally to resistor melting. Finally, the failure mechanism on the transistor level was investigated. Via focused ion beam (FIB) etching and microscopic observation, it was found that the failure originates from electrothermally induced melting in two regions: the gate area near the HEMT input terminal and the region adjacent to the gate–source interface. Furthermore, simulations were conducted to investigate the evlution of internal electrical and thermal characteristics within the GaN HEMT. The simulation results demonstrate that the concentrated electric field and increased current density in the gate–source region lead to a rise in local lattice temperature—consistent with the damage morphology observed in experiments. These simulation results provide detailed insights into the internal evolution process of the failure and strongly support the aforementioned conclusions.