Design, Simulation, and Optimization of a High Voltage SiC Semiconductor Opening Switch Diode

This research presents the first simulations of an ultra-high voltage Silicon Carbide (SiC) Semiconductor opening switch (SOS) diode, demonstrating the viability of transition to wide bandgap semiconductors for pulsed-power electronics applications. Silicon-based SOS diodes have previously been shown as viable drivers in applications such as plasmochemical reactors, nitrogen laser pumping, and for the generation of high-current electron beams to the generation of high-power microwaves, signifying their use in pulsed-power electronics. In all historical instances, the solution to increasing system voltage and power handling capabilities is to stack tens to hundreds of Si SOS diodes in series. The transition to SiC SOS diodes will reduce the required number of devices by up to 20X, thus increasing system reliability and efficiency while decreasing system size. The SOS diode simulations' foundation is built upon the DC and transient characterizations of a commercially manufactured SiC drift step recovery diode (DSRD). A matching Silvaco Victory Device model is created for the DSRD using the characterization results. This process allows the extraction of material properties and verifies the necessary Victory Device physics models required for modeling SiC opening diodes. An optimization study was conducted to determine the effects of altering seven device structure parameters to generate the ideal SOS diode design. This SOS diode structure is used to create the first modeled demonstration of the SOS effect in Silicon Carbide. Demonstrating the SOS effect in SiC is verified by modeling the time-dependent electric field and free carrier concentration through the device in a pulsed circuit. The same optimized structure is used to demonstrate a higher conversion efficiency system. Lastly, five optimized devices are stacked in series to produce a 100 kV 180 MW pulse power system.