High Performance Termination of Power Devices with Multi-epi Method

This paper presents a high-performance termination based on multi-epi method, where an intrinsic layer is used in the top layer epitaxy, and the field limiting rings (FLR) and field plate (FP) are also adopted. The introduction of the surface intrinsic layer can improve the internal electric field and meet the breakdown voltage (BV) requirements of the termination under the condition of a small termination area. As an example, simulation result of a 1200V fast recovery diode (FRD) shows that the BV is up to 1410V under a termination length of 220µm. Compared with traditional FLR and FP structures, the termination length is reduced by 58% and the BV is increased by 19%. The proposed structure can be well applied to existing high voltage power devices.