Reversely switched dynistor: From Si to SiC

The characteristics of the pulsed power switch reversely switched dynistor(RSD) based on Si and SiC are analyzed by contrast in the view of the device models, and the advantages of the RSD fabricated by the wide bandgap semiconductor SiC are illustrated in this paper. By establishing the two-dimensional numerical models of the devices, combined with the external circuit models, the blocking characteristics and the turn-on characteristics could be simulated, respectively. The results show that: (1) SiC RSD could get the same blocking voltage as Si RSD with about 1/10 width and 100 times doping concentration of the drift region. (2) It is important for both Si RSD and SiC RSD to accumulate enough precharges in the triggering process, so as to turn on normally and reduce the residual voltage at the front edge of the pulse. (3) For the quasi-static voltage drop in the turn-on process, only when the voltage rate is high enough(~>6kV) can SiC RSD have advantage over Si RSD. A kind of compact pulse generation circuits based on the PCB level of RSD are also developed in this paper in order to reduce the volume and enhance the output di/dt.