中子辐照对GaN高电子迁移率晶体管重离子诱导漏电流退化影响的研究

This study investigates the influence of neutron irradiation on the heavy-ion-induced leakage degradation in p-GaN gate high electron mobility transistors (HEMTs). Neutron irradiation experiments at different energies were conducted, revealing a positive shift in the threshold voltage ( V_ TH ) and a reduction in the output saturation drain current ( I_ DS ). Subsequent Ta-ion irradiation experiments were conducted to investigate the leakage current degradation during the irradiation process. We observed that devices pre-irradiated with neutrons exhibit weaker leakage degradation during heavy-ion irradiation compared to unirradiated devices, suggesting a suppression effect of neutron irradiation on heavy-ion-induced leakage degradation. Simulations using technology computer-aided design (TCAD) and GEometry ANd Tracking 4 (Geant4) were performed to elucidate the underlying mechanisms. The results revealed that neutron irradiation introduces acceptor-like traps in GaN devices, reducing the electron concentration generated during heavy-ion irradiation, thereby suppressing drain leakage current ( I_ D ). Furthermore, the lattice temperature and impact generation rate during irradiation were observed to decrease, hindering the formation of leakage paths and mitigating damage in the drain region. This study represents the first observation of neutron irradiation suppressing heavy-ion-induced leakage degradation in GaN devices, thus providing a theoretical foundation for improving the radiation hardness of GaN HEMTs against leakage degradation.