Design and Simulation Analysis of 1.2 kV SiC JBS Diodes with High Performance and Avalanche Capability

• Main Authors: Xu, Leilei, Liu, Yancong, Yuan, Hao, Tang, Xiaoyan, Wang, Xuanjie, Zou, Fengzhen, Song, Qingwen, Zhang, Yuming
• Format: Conference Proceeding
• Language: English
• Subjects: avalanche capability; current spreading layer; Doping; Electric fields; JBS; Performance evaluation; Reliability; Safety; SiC; Silicon carbide; Structural rings
• ISSN: 2575-2642
• DOI: 10.1109/ICRMS59672.2023.00227

In this study, a 1.2 KV SiC JBS diode with a current spreading layer (CSL) is designed. It is observed that the forward conduction characteristics of the device are enhanced substantially compared with the conventional JBS by decreasing the specific on-resistance effectively when the reverse breakdown voltage can still satisfy the requirement of 1.2 KV. Additionally, the avalanche capability of JBS diodes with different CSL doping concentrations is studied further. It is observed that the avalanche current is transferred from the terminal region with a smaller area to the active region with a larger area because the addition of the CSL structure increases the electric field strength in the active region. Moreover, with the increase in doping concentration, the electric field strength in the source region is enhanced. This results in an increase in the avalanche current flowing from the active region. This, in turn, effectively suppresses the maximum temperature of the current-sensitive terminal region. It is demonstrated that the maximum temperature of the CSL structure decreases by 53.8% compared with that of the conventional JBS structure. Therefore, it is inferred that the CSL structure is an effective solution to improve the avalanche capability of 4H-SiC JBS diode.