Physics-based spice model on the dynamic characteristics of silicon carbide Schottky barrier diode

Silicon carbide Schottky barrier diodes (SiC SBDs) are poised to replace silicon PIN diodes as a new choice for the high power and high frequency applications. However, SiC SBDs suffer from ringing which may induce additional power losses when applied in chopper circuit, regarded as the interaction among the depletion capacitance, depletion resistance, parasitic stray inductance and series resistance. The existing SiC SBD models generally treat the resistances as constants and ignore the influence of the MOS, which deviate the switching commutation process significantly on the ringing frequency and amplitude. In this study, a more accurate Spice model of SiC SBD has been developed in which voltage dependent non-linear depletion capacitance and resistances are all considered in the transient analysis based on semiconductor physics, while the Miller capacitance of the MOS performing as a switch in the circuit is also taken into account. The improved model and analysis are validated by the better agreement with the experiments compared with the existing models on the dynamic characteristics.