High Voltage, Low On-Resistance 4H-SiC BJTs with Improved Junction Termination Extension
In this work, implantation-free 4H-SiC bipolar transistors with two-zone etched-JTE and improved surface passivation are fabricated. This design provides a stable open-base breakdown voltage of 2.8 kV which is about 75% of the parallel plane breakdown voltage. The small area devices shows a maximum dc current gain of 55 at Ic=0.33 A (JC=825 A/cm2) and VCESAT = 1.05 V at Ic = 0.107 A that corresponds to a low ON-resistance of 4 mΩ•cm2. The large area device shows a maximum dc current gain of 52 at Ic = 9.36 A (JC=312 A/cm2) and VCESAT = 1.14 V at Ic = 5 A that corresponds to an ON-resistance of 6.8 mΩ•cm2. Also these devices demonstrate a negative temperature coefficient of the current gain (β=26 at 200°C) and positive temperature coefficient of the ON-resistance (RON = 10.2 mΩ•cm2).