SPEC student Xixi Lou is testing advanced SiC power chip
SPEC designed, fabricated, and characterized an implantation-free 3 kV 4H-SiC Bipolar Junction Transistor (BJT). 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 devices and an on-resistance of 39.7mΩ·cm2 for large-size devices. The measured current gain for devices with additional anneal process is 21.