Area- and efficiency-optimized junction termination for a 5.6 kV SiC BJT process with low ON-resistance

Implantation-free mesa-etched 4H-SiC bipolar junction transistors (BJTs) with a near-ideal breakdown voltage of 5.6 kV (about 92% of the theoretical value) are fabricated, measured and analyzed by device simulation. An efficient and optimized termination; area-optimized three-zone junction termination extension (O-JTE) is implemented, reducing the total area (and substrate cost) by about 30% compared to the traditional JTE designs. A maximum current gain of β = 44 at a current density of 472 A/cm², and a specific on-resistance of R_ON = 18.8 mΩ.cm² is obtained for the device. The device shows a negative temperature coefficient of the current gain (β = 14.5 at 200 °C) and a positive temperature coefficient of on-resistance (R_ON = 57.3 mΩ·cm² at 200 °C).