Since the technical progress of SiC power metal oxide semiconductor field effect transistor(MOSFET) were published in 2017, the device structure design were optimized in view of the high specific onresistance (RON,SP). Our research group has improved the key processing technology to reduce the RON,SP of 1 200 V SiC MOSFET from 8 mΩ·cm2 to 4.8 mΩ·cm2. Using the new design methods and fabrication processes, high performance SiC MOSFET for voltage ratings from 6.5 kV up to 15 kV were achieved. The RON,SP is 144 mΩ·cm2 for the 10 kV devices and 204 mΩ·cm2 for the 15 kV devices which is close to the SiC theoretical limit.