Reliable Operation of SiC Junction-Field-Effect-Transistor Subjected to over 2 Million 600-V Hard Switch Stressing Events

A necessity for the successful commercialization of SiC power devices is their long term reliability under the switching conditions encountered in the field. Normally-ON 1200 V SiC JFETs were stressed in repetitive hard-switching conditions to determine their fault handling capabilities. The switching pulses were generated from an RLC circuit, where energy initially stored in capacitors discharges through the JFET into a resistive load. The hard-switching included one million repetitive pulsed hard-switching events at 25 °C from a drain blocking-voltage of 600-V to an on-state current of 67 A, and an additional one million 600-V/63-A pulsed hard-switching events at 150 °C. The JFET conduction and blocking-voltage characteristics are virtually unchanged after over two million hard switching events proving the devices are reliable for handling high surge-current faults like those encountered in bidirectional circuit breaker applications.°