Analytical model and optimization strategy for SiC floating junction JBS diodes.

Conventional SiC power semiconductor devices are disturbed by “SiC limit”, but the floating junction (FJ) structure can overcome the limit. This article classifies FJ breakdown model into two types based on the FJ doping concentration: “Incompletely Depleted Floating Junction” (IDFJ) and “Fully Depleted Floating Junction” (FDFJ). The focus of this article is on the model establishment and design optimization of the FJ JBS diode. Analytical models of conducting state and blocking state for FDFJ are established and verified using TCAD simulation. The research findings indicate that adjusting the floating junction doping concentration can significantly improve the performance of SiC JBS diodes. An optimal Baliga's Figure of Merit (BFOM) of 12.44 GW/cm2 (BFOM = 4BV2/Ron-sp) can be achieved, which represents a 31.8% improvement over the FDFJ (non-optimal) JBS diode. These outcomes are promising and indicate that SiC JBS diodes may have many potential applications in power electronics devices.