Physical Explanation for the Higher Sensitivity to Ion-Induced Burnout in SiC Schottky Diodes Compared to Si Schottky Diodes

SiC has a higher critical electric field compared to Si, which is promising for power applications. However, the susceptibility of SiC Schottky barrier diodes (SBDs) to heavy ions is recognized as a critical issue due to Single Event Burnout (SEB) and Single Event Leakage Current (SELC). Despite extensive research, a comprehensive understanding of the main mechanisms underlying heavy ion-induced failures in SiC devices remains missing. This work compares the physical mechanisms in SiC and Si Schottky diodes using TCAD modeling. The results show that the high critical electric field, a key advantage of SiC devices, is also the primary factor behind their susceptibility to heavy ion irradiation. In Si diodes, impact ionization limits the electric field, reducing Joule heating and mitigating burnout risk. However, once impact ionization occurs in SiC diodes, the electrostatic potential is already too high, triggering the mechanism that causes the burnout. Additionally, Band-to-Band Tunneling (BBT) plays a pivotal role in this triggering of SEB.