Silicon carbide temperature-tolerant power electronics for dual use systems applications

Because of their wide bandgap, high operating temperature (to 500°C), high breakdown voltage (10X that of silicon) and other unique electronic properties, power switches and diodes based on silicon carbide (SiC) offer significant potential performance advantages compared to silicon-based devices in terms of reliability, higher immunity to thermal runaway, reduced switching losses, and higher current density. When combined with the high thermal conductivity of SiC (like copper), significant savings in system cooling requirements, weight and cost are likely for many aircraft, shipboard, vehicle and utility power conversion applications. Application for robust sensors and controls in more conventional systems are also visualized. Current research is aimed to turn such promise into the demonstrations required for initial product applications by addressing critical technical issues to realize operational discrete power devices. These include vertical MOSFETs, static induction transistors, gate tum-off thyristors (GTOs), MOS turn-off thyristors (MTOs) and companion diodes (Agarwal et al., 1996), (Palmour et al., 1996), (Shenoy et al., 1996). This presentation addresses the relative benefits of various power device structures, emphasizing how the special properties of SiC enhance the utility of specific devices compared to their Si-based counterparts. We have already demonstrated a 1100 V MOSFET, a 700 V GTO operating at 350°C, and diodes with 1000 V breakdown and power densities of 1000 A/cm²