600-V 27-mΩ normally off SiC junction field effect transistors for high-efficiency power supply

Normally-off SiC junction field effect transistors (JFETs) with high blocking voltage and low gate leakage current were developed by localized current-path doping (LCD). Numerical simulation of electric field revealed that LCD effectively decreases the on-resistance of SiC JFETs without degrading blocking voltage. On the basis of the obtained simulation results, 600-V 27-mΩ normally off SiC JFETs were fabricated by LDC. The gate leakage current of the fabricated JFETs was suppressed by surface oxynitridation. By applying in a server power supply, we found that these improved JFETs decreased power loss due to FETs by 66%.