600-V symmetrical bi-directional power switching using SiC vertical- channel JFETs with reliable edge termination

摘要

Numerous high-voltage applications require symmetrical bi-directional power flow control and protection circuitry. While mechanical contactors and circuit breakers provide bidirectional fault protection, they have slow actuation and suffer severe degradation during repeated fault isolation. The normally-on (N-ON) SiC vertical-channel Junction-Field-Effect-Transistor (VJFET) is an efficient solution for bi-directional circuit-breaker applications due to its low conduction/switching losses, +500°C operational capability, ON-state match of the no-fault operating mode of the system, efficient gate-drive operation under unipolar biasing, and majority carrier device scalability. Efficient 600-V/10-A symmetrical bi-directional power flow was demonstrated using 0.1-cm~2 1200-V rated N-ON VJFETs with a gate driver applying 0-V and -34 V gate biases during the ON and OFF states, respectively. A self-aligned trenched guard-ring structure provides reliable edge termination.