Characteristics comparison of SiC and Si drift step recovery diode

Abstract

In order to evaluate the prospects of drift step recovery diode (DSRD) based on Silicon Carbide (SiC) in pulsed power field, the characteristics of DSRD based on SiC and Silicon (Si) are compared. The simulation model of the circuit based on Sentaurus TCAD is established and a trigger circuit using the saturated transformer is adopted. The simulation results show that under the same conditions, SiC DSRD has advantages in the aspect of rise time and it is less affected by pedestal effect, which is detrimental to the pulse quality and produces energy loss. The advantage of Si DSRD is that the amplitude of the output pulse voltage is high. By testing the voltage and the rise time of the output pulse, the influence of different factors including turns ratio and input voltage are discussed. For single chip of SiC DSRD with 5 kV blocking voltage, the turns ratio of transformer should be 1:5 to ensure that the parasitic inductance of transformer is low and the input voltage should be more than 500 V to guarantee that the magnetic core can be saturated. For Si DSRD stacked in series, the rise time and the width of output pulse is relatively stable and have little correlation with the changes of the input voltage, the forward pumping time and the circuit parameters. The experiment proves that SiC DSRD and Si DSRD have the advantages of the rise time and the output pulse voltage, respectively, which is consistent with the simulation results.