A Novel Design Variation of a Monolithically Integrated SiC Circuit Breaker

This paper provides a thorough design study of a two-pole solid-state circuit breaker (SSCB) device for 900 V DC applications supported by quasi-static two-dimensional TCAD simulations. Building on the work of Boettcher et al. using 4H-SiC JFET technology with monolithic integration of an n-channel JFET (nJFET) and a p-channel JFET (pJFET), the proposed design replaces the horizontal nJFET with a vertical structure [1]-[3]. This change eliminates the need for a second epitaxial layer and reduces the number of ion implantation steps from six to three, thereby simplifying the manufacturing process. Numerical TCAD simulations reveal that the novel SSCB design enables independent tuning of threshold and breakdown voltage. In the pJFET, adjustments in channel depth and doping concentration allow the blocking voltage window to be enhanced from 450 V to over 800 V, while maintaining a breakdown voltage of approx. 900 V. These findings indicate that the proposed SSCB design offers improved performance and fabrication efficiency for high voltage DC applications.