Fabrication and characterization of high current gain (β=430) and high power (23 A-500 V) 4H-SiC hybrid Darlington bipolar transistor

This paper reports the demonstration of a hybrid Darlington bipolar junction transistor (BJT) with a high current gain and a power handling capability substantially higher than the power level of previously reported SiC Darlington BJTs. The Darlington transistor has been tested up to a collector current of 23.5 A and BV_ceo of 500 V, showing a large-signal dc common emitter current gain (β) of 430 and an ac common emitter current gain of 650. Also reported for the first time are the Darlington characteristics up to an ambient temperature of 150°C as well as inductively loaded half-bridge inverter switching characteristics. Comparison between a single SiC BJT and a Darlington BJT is made based on the dc and switching results at both room temperature and 150°C, and the results are reported.