1000-V, 30-A 4H-SiC BJTs with high current gain

This paper presents the development of 1000 V, 30 A bipolar junction transistor (BJT) with high dc current gain in 4H-SiC. BJT devices with an active area of 3 x 3 mm(2) showed a forward on-current of 30 A, which corresponds to a current density of 333 A/cm(2), at a forward voltage drop of 2 V. A common-emitter current gain of 40, along with a low specific on-resistance of 6.0 mOmega.cm(2) as observed at room temperature. These results show significant improvement over state-of-the-art. High temperature current-voltage characteristics were also performed on the large-area bipolar junction transistor device. A collector current of 10 A is observed at V-CE, = 2 V and I-B = 600 mA at 225 degreesC. The on-resistance increases to 22.5 mOmega.cm(2) at higher temperatures, while the de current gain decreases to 30 at 275 degreesC. A sharp avalanche behavior was observed at a collector voltage of 1000 V. Inductive switching measurements at room temperature with a power supply voltage of 500 V show fast switching with a turn-off time of about 60 ns and a turn-on time of 32 ns, which is a result of the low resistance in the base.