1800 V NPN bipolar junction transistors in 4H-SiC

The first high voltage npn bipolar junction transistors (BJTs) in 4H-SiC ha ve been demonstrated. The BJTs were able to block 1800 V in common emitter mode and showed a peak current gain of 20 and an on-resistance of 10.8 m Om ega .cm(2) at room temperature (I-C = 2.7 A @ V-CE = 2 V for a 1 mm x 1.4 m m active area), which outperforms all SIC power switching devices reported to date. Temperature-stable current gain was observed for these devices. Th is is due to the higher percent ionization of the deep level acceptor atoms in the base region at elevated temperatures, which offsets the effects of increased minority carrier lifetime at high temperatures. These transistors show a positive temperature coefficient in the on-resistance characteristi cs, which mill enable easy paralleling of the devices.