Optimal edge termination for high oxide reliability aiming 10kV SiC n-IGBTs

Abstract

The edge termination design strongly affects the ability of a power device to support the desired voltage and its reliable operation. In this paper we present three appropriate termination designs for 10kV n-IGBTs which achieve the desired blocking requirement without the need for deep and expensive implantations. Thus, they improve the ability to fabricate, minimise the cost and reduce the lattice damage due to the high implantation energy. The edge terminations presented are optimised both for achieving the widest immunity to dopant activation and to minimise the electric field at the oxide. Thus, they ensure the long-term reliability of the device. This work has shown that the optimum design for blocking voltage and widest dose window does not necessarily give the best design for reliability. Further, it has been shown that Hybrid Junction Termination Extension structure with Space Modulated Floating Field Rings can give the best result of very high termination efficiency, as high as 99%, the widest doping variation immunity and the lowest electric field in the oxide.