Analysis of Floating Limiting Rings Termination Under Repetitive Avalanche Current Stress for 4H-SiC JBS Rectifiers

Abstract

The reverse breakdown characteristics of 4H-SiC Junction Barrier Schottky (JBS) rectifiers adopting the different floating limiting rings (FLRs) termination structures are experimented and analyzed under the repetitive avalanche current stress. The experimental results indicate that the breakdown voltage (BV) shift of the device after the repetitive avalanche current stress is highly dependent on the FLRs design, which determines the distributions of the surface electric field and avalanche current at avalanche condition. It is proved that the uniform surface electric field distribution of the FLRs structure at avalanche condition is helpful for the device achieve to achieve better BV shift robustness on the repetitive avalanche current stress. Additionally, the FLRs structure, which has smaller S1 and enough Nr, can present both higher BV and excellent BV shift robustness on the repetitive avalanche current stress.