Recent advances in silicon carbide MOSFET power devices

Abstract

Emerging silicon carbide (SiC) MOSFET power devices promise to displace silicon IGBTs from the majority of challenging power electronics applications by enabling superior efficiency and power density, as well as capability to operate at higher temperatures. This paper reports on the recent progress in development of 1200V SiC power MOSFETs. Two different chip sizes were fabricated and tested: 15A (0.225cm×0.45cm) and 30A (0.45cm×0.45cm) devices. First, the 30A MOSFETs were packaged as discrete components and static and switching measurements were performed. The device blocking voltage was 1200V and typical on-resistance was less than 50 m¿ with gate-source voltages of 0V and 20V, respectively. The total switching losses were 0.6 mJ, over five times lower than the competing devices. Next, a buck converter was built for evaluating long-term stability of the MOSFETs and typical switching waveforms are presented. Finally, the 15A MOSFETs were used for fabrication of 150A all-SiC modules. The module on-resistance values were in the range of 10 mQ, resulting in the best-in-class on-state voltage values of 1.5V at nominal current. The module switching losses were 2.3 mJ during turn-on and 1 mJ during turn-off, also significantly better than competing designs. The results validate performance advantages of the SiC MOSFETs, moving them a step closer to power electronics applications.