High-temperature dynamic characterization of 4H-silicon carbide p-n diodes

There is an increasing military and industrial need for power semiconductor devices rated beyond the existing military temperature requirement of 125°C. The current More Electric Initiative (MEI) demands high temperature and high power electronics for use in power management and distribution, actuator motor control, on-site sensors, and data bus electronics. In an attempt to develop electronic power devices for applications that require reliable operation above 350°C, low current forward and reverse bias static and dynamic characterization was performed on 4H-SiC p⁺-n diodes in the temperature range of 25°C to 330°C in a high vacuum chamber. The dynamic measurements involved rectifier efficiency as a function of temperature and frequency, power dissipation for various duty cycles in this temperature range and reverse recovery characteristics as a function of temperature and rate of change of commutation current. Static characteristics revealed a decrease in threshold voltage from 2 volts at 25°C to 1.25 volts at 230°C