Design and H3TRB Test on 650V SiC-JBS Diodes

This paper presents the design and fabrication of a 650V/10A silicon carbide Junction Barrier Schottky (SiC JBS) diodes. They underwent a H3TRB test, and the failed devices were analyzed to determine the failure mechanisms. Various optimization strategies were proposed. After the experiments, most of the 39 diodes showed a certain degree of increase in leakage current after the 1000-hour H3TRB test, while their forward characteristics were largely unaffected. Additionally, one device experienced a sharp increase in leakage current and lost its breakdown capability. The failure of the devices can be attributed to a significant increase in leakage current at the terminal ring corners induced by water vapor, leading to thermal accumulation and burn marks. The differential thermal expansion coefficient between the passivation layer and the metal caused the passivation layer to crack and delaminate under thermal stress, ultimately resulting in the loss of breakdown capability and device failure. Different improvement schemes were proposed, including optimizing the terminal ring structure, passivation layer materials, and encapsulation material selection. The research in this paper provides strong guidance for the design of reliable silicon carbide power devices.