Robust double-ring junction termination extension design for high voltage power semiconductor devices based on 4H-SiC

In this study, a robust double-ring junction-termination-extension (DR-JTE) for highvoltage pn-diodes is presented and analyzed using numerical simulations. As figured out, the DRJTE reduces the electrical field at both, the edge of the single-JTE region and the mesa-transition, respectively. Thereby, due to the reduction of the electrical field, the maximum breakdown voltage is increased to 91.5% of the theoretical, parallel-plane breakdown voltage of 6.5 kV and the maximum acceptable deviation of the optimum implantation dose is twice than that of the single- JTE structure. Furthermore, due to the internal ring, the mesa-transition is shielded from the electrical field and therefore the breakdown voltage is much less affected by the angle of the mesa.