Evaluation of 4H SiC bipolar junction transistors

4H-SiC bipolar junction transistors (BJTs) demonstrate excellent current carrying and blocking capabilities, and offer good high-temperature performance. Moreover, these devices are easier to parallel than their Si analogues due to negative current gain temperature coefficient In contrast to vertical MOSFETs and JFETs, these devices do not have junction discontinuities in the active region, which makes these devices easily scalable to high blocking voltage requirements. This experiment will help determine the safe operating areas of 1mm², 4mm², 9mm², and Darlington structure SiC BJTs constructed by CREE. The eventual goal of this work is to produce devices capable of blocking 1200V and operating at a maximum collector current of 10A. Ideally gains of 8 or more are desired at temperatures of 150°C. These devices will be characterized at temperatures up to 150°C. Next they will be put into a system containing a push-pull circuit, which will be used in to control the on and off states of the BJT under test. This report will serve as to document the operational status of the present devices and as feedback to CREE in order to guide the production of future devices. These devices were tested using single-shot and repetitive pulsing. The devices were tested individually, as well as in parallel pair configurations. During each of these experiments the devices were tested from room temperature to 150°C