In this work, 600V 4H-SiC MPS diodes were designed, fabricated and tested. The diodes were designed with a multi-step junction termination extension (MJTE) to improve the blocking voltage. The highest forward current capability of a packaged MPS diode showed a current of 50A at 2V and 140A at 4V. The SiC MPS diode reverse voltage showed excellent suppression of the Schottky leakage current at temperatures up to 250degreesC. Switching measurements using a half-bridge circuit, at currents up to 230A, showed a substantial reduction in diode dissipation, compared to a state of the art Si diode; a 47% energy loss reduction at room temperature(RT) and 84% at 200degreesC. The IGBT energy loss reduction, when using an MPS diode, was 15% at room temperature and 45% at 150degreesC. The diodes should result in improved efficiency when used in electric vehicles.