Physical modeling and design optimization of 4H-SiC insulated gate bipolar transistors for dv / dt reduction

The extremely high dv / dt of 4H-SiC insulated gate bipolar transistor (IGBT) becomes the major concern in its next-generation large-volume power conversion applications because severe electromagnetic interference (EMI) is induced. However, the root reason for its high dv / dt and the method of suppressing EMI have not been extensively investigated yet. In this paper, we proposed a novel physical model for SiC IGBT to identify the major limiting device design parameters of dv / dt during switching transients. The influences of SiC IGBT’s design parameters on its dv / dt and power dissipation are quantitatively analyzed by means of the physical model. Comparisons between the theoretical predictions and technology computer-aided design simulation results validate the physical model. The results on design optimization of a 18 kV n -channel SiC IGBT shows that 80% reduction of dv / dt and 60% reduction in turn-off power dissipation are achieved simultaneously without sacrificing its forward voltage drop.