This paper presents a comparative study on the short-circuit and surge current withstanding capabilities and the static and turn-on switching characteristics of commercial 1.2-kV SiC SBD-embedded MOSFETs. The results confirmed that MOSFETs with a larger SBD area ratio had higher leakage current through the SBD during short-circuit transients due to a higher electric field and lattice temperatures as high as roughly 1120 K at the SBD, which resulted in reduced short-circuit withstanding capabilities. It was also found that MOSFETs with a smaller SBD area ratio had reduced surge-current capabilities in embedded SBDs. We conclude that is not due to the small SBD area ratio but to a weak bipolar operation of the JBS rectifiers even in high current regions.

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