Comparison of Commutation Transients of Inverters with Silicon Carbide JFETs with and without Body Diodes

An inverter could be built by using silcon carbide power switches only. This can be done by using SiC JFETs which can conduct current in both directions. An interesting question is how an inverter using SiC JFETs with a body diode compares with an inverter using SiC JFETs without body diodes. This will be discussed in this paper. I. I NTRODUCTION Silicon carbide has been pointed out for long as the material that will replace silicon as the dominating semiconductor mate- rial for switching power applications (4). The reason for th is is that the drift resistance in SiC power devices can theoretic ally be up to 700 times lower than in silicon power devices of equal area while the drift region can sustain the same blocking voltage (6). Additionally, silicon carbide can withstand higher te mpera- tures than silicon. In inverters today the IGBT is the normally used component. Since an IGBT cannot conduct current in the reverse direction, an anti-parallell power diode is needed. However, a SiC JFET can conduct current in both forward and reverse direction elim- inating the need for a power diode as first suggested in (1).