Heavy-ion induced single event effects and latent damages in SiC power MOSFETs

The advantages of silicon carbide (SiC) power MOSFETs make this technology attractive for space, avionics and high-energy accelerator applications. However, the current commercial technologies are still susceptible to Single Event Effects (SEEs) and latent damages induced by the radiation environment. Two types of latent damage were experimentally observed in commercial SiC power MOSFETs exposed to heavy-ions. One is observed at bias voltages just below the degradation onset and it involves the gate oxide. The other damage type is observed at bias voltages below the Single Event Burnout (SEB) limit, and it is attributed to alterations of the SiC crystal-lattice. Focused ion beam (FIB) and scanning electron microscopy (SEM) were used to investigate the damage site. Finally, a summary of the different types of damage induced by the heavy ion in SiC MOSFETs is given as a function of the ion LET and operational bias.