600V-30A 4H-SiC Junction Barrier Schottky（JBS）diodes were designed and fabricated using SiC epitaxy and device technology. SiC JBS diodes were packaged in Si IGBT module，and switching measurements were done at 125°C. As free-wheeling diode for Si IGBT, 600V SiC JBS diode was compared to 600V ultra-fast diode from International Rectifier. SiC diode achieved 90% recovery loss reduction and corresponding IGBT showed 30% lower turn-on loss. However, SiC JBS diode has larger on-state voltage drop due to small chip area. On-state power loss will be lowered by increasing SiC chip area.