Résumé
This work compares Si and SiC VDMOSFETs under heavy-ion irradiation using TCAD simulations. The analysis covered two representative radiation environments: a moderate case using Al and Na ions, representative of low-LET atmospheric neutron-induced secondaries, and a worst-case scenario using high-LET Xe ions relevant to space conditions. Results show that SiC devices exhibit higher susceptibility to SEGR and SEB compared to their Si counterparts, even under moderate conditions, due to their higher critical electric field and structural characteristics. Furthermore, the simulations reveal that once a failure is initiated, a dense plasma column propagates toward the drain, driving Joule heating, impact ionization, and extensive thermal damage across multiple transistors, in agreement with experimental post-irradiation observations. These findings demonstrate the importance of combining experimental evidence with physics-based TCAD modeling to achieve a comprehensive understanding of radiation-induced failure mechanisms in power MOSFETs