Comparison of the Single-Event Response for SiC MOSFETs With Linear and Square Cells

This study reports on the differential susceptibility of SiC metal-oxide-semiconductor field-effect transistors (MOSFETs) with square and linear cell layouts to single-event irradiation. Under irradiation by 1443 MeV181Ta ions, square cell exhibits higher susceptibility to single-event effects (SEEs) compared to linear cell. An uncommon leakage current path, located between the gate and source, has been identified in square cell devices. Layer-by-layer focused ion beam (FIB) cutting of the square cell device revealed that both the gate and source are penetrated, with damage distributed along the current path. 3-D TCAD simulations indicated that the lattice temperature rise in SiC MOSFETs is localized along the current path, suggesting that material damage is likely thermally induced. This study shows that the square cell exhibits stronger electro-thermal coupling due to higher JFET region electric field and current crowding caused by the sharp corners p-base/n-junction and electrode, whereas the linear cell, featuring a linear p-base/n-junction and electrode, achieves smoother current distribution, leading to stronger SEE resilience. Finally, a square cell with a circular electrode is proposed, which maintains low specificon-resistance while partially mitigating current crowding, providing a useful reference for radiation-hardened SiC MOSFET design in aerospace power management, satellite systems, and deep-space exploration.