3kV 6.7mΩ·cm2 4H-SiC BJT with An Effective Junction Termination Extension (JTE)

In this paper, an implantation-free 3 kV 4H-SiC Bipolar Junction Transistor (BJT) is designed, fabricated, and characterized. With a 40μm-wide Four-step Junction Termination Extension (JTE), an open base breakdown voltage (BVCEO) and an open emitter breakdown voltage (BVCBO) of more than 3000V are measured. The total width of the JTE is less than two times of the drift thickness (23μm), which can be considered as highly area efficient. The designed BJT has a 1.2μm narrow base width with 1×1017cm-3 doping, where implantation-free Ohmic contact was achieved. The BJT exhibits an excellent on-resistance of 6.7mΩ·cm2 for small size device and an on-resistance of 39.7mΩ·cm2 for large size device. The measured current gain for devices with additional anneal process is 21.