A Short-Circuit Safe Operation Area Identification Criterion for SiC MOSFET Power Modules

This paper proposes a new method for the investigation of the short-circuit safe operation area (SCSOA) of stateof- the-art SiC MOSFET power modules rated at 1.2 kV based on the variations in SiC MOSFET electrical parameters (e.g., short-circuit current and gate-source voltage). According to the experimental results, two different failure mechanisms have been identified, both reducing the short-circuit capability of SiC power modules with respect to discrete SiC devices. Based on such failure mechanisms, two short-circuit safety criteria have been formulated: 1) the short-circuit-current-based criterion; and 2) the gate-voltage-based criterion. The applicability of these two criteria makes possible the SCSOA evaluation of SiC MOSFETs with some safety margins in order to avoid unnecessary failures during their SCSOA characterization. SiC MOSFET power modules from two different manufacturers are experimentally tested in order to demonstrate the procedure of the method. The obtained results can be used to have a better insight of the SCSOA of SiC MOSFETs and their physical limits.