A Comprehensive Design of Edge Terminations for High-Voltage SiC Devices Utilizing P-Type Epitaxial Layer

We proposed 3.3 kV SiC PiN diodes with edge termination structures using a mesa etched P-type epitaxial layer instead of Al implanted layer. This method simplifies the fabrication procedure and provides advantages for enabling the simultaneous formation of both an active and an edge termination region. Ring-assisted junction-termination-extension (RA-JTE) and mesa RA-JTE (MRA-JTE) were designed on the P-type epaxial layer, and their blocking characteristics were compared with single-zone JTE. In order to enhance the blocking capabilities of SiC power devices under circumstances involving process deviations, such as oxide charge variations, we employed space modulated multiple-floating P+ rings within the epitaxially grown JTE region. The MRA-JTE exhibits high breakdown voltage in a wide range of JTE concentration (NJTE) and fixed charge in the field oxide (QF) due to the combination of P+ rings and two-step mesa etched regions. This paper elucidates the mechanisms for the stable blocking characteristics exhibited by MRA-JTE.