The effect of emitter implant and anneal on high-voltage 4H-SiC BJTs

We previously reported the first implanted-emitter bipolar transistor in 4H-SiC. The device showed a record-high common emitter current gain of 40, and forward drop of 1 V at forward current density of 50A/cm/sup 2/. The open-base breakdown voltage was less than 60 V due to the very small base width (<0.2 μm). In this work, improved epi-base, implanted-emitter, npn bipolar junction transistor is reported with increased base width and improved emitter anneal. The devices showed a blocking voltage of 500 V and maximum common emitter current gain of 8. Negative temperature coefficient is observed.