A trade-off between nominal forward current density and surge current capability for 4.5kV SiC MPS diodes

There is a trade-off between nominal forward current density and surge current capability for 4.5kV SiC MPS diodes. This paper explains the physical mechanisms underlying this trade-off and identifies the relevant design parameters. The dependencies of this trade-off on the layout parameters and physical parameters are described by analytical relations (compact model). An equivalent lumped element circuit is set up for an intuitive interpretation of the functional components of a SiC MPS diode. Eventually, we investigate several novel device structures with a view to improving the forward characteristics under regular and overcurrent operating conditions.