20 A, 1200 V 4H-SiC DMOSFETs for energy conversion systems

4H-SiC DMOSFETs designed to conduct up to 20 A and block in excess of 1200 V are described, and a performance comparison with comparably rated Si MOSFETs and IGBTs is presented. The 4H-SiC DMOSFETs show comparable to slightly improved on-state losses compared to the Si IGBTs and significantly improved performance over the Si MOSFET. Leakage currents of the 4H-SiC DMOSFETs are two orders of magnitude lower than those of the Si switches. Gate charge of the 4H-SiC DMOSFET is also reduced compared to the Si switches; moderately as compared to the Si IGBTs and quite significantly compared to the Si MOSFET, and total switching energy losses are 50% to 70% lower than those of the Si switches. The performance advantages in conduction and switching losses of the 4H-SiC DMOSFET permits operation to much higher frequencies and/or at higher junction temperatures than is achievable with the Si counterpart switches.