On the suitability of 3C- Silicon Carbide as an alternative to 4H- Silicon Carbide for power diodes

Major recent developments in growth expertise related to the cubic polytype of Silicon Carbide, the 3C-SiC, coupled with its remarkable physical properties and the low fabrication cost, suggest that within the next years, 3C-SiC devices can become a commercial reality. Inevitably, a comparison to the most well-developed polytype of SiC, the 4H-SiC, should exist. It is, therefore, important to develop finite element method techniques and models for accurate device design, analysis, and comparison. It is also needed to perform an exhaustive investigation with scope to identify which family of devices, which voltage class, and for which applications this polytype is best suited. In this paper, we validate the recently developed technology computer-aided design (TCAD) material models for 3C-SiC and those of 4H-SiC with measurements on power diodes. An excellent agreement between measurements and TCAD simulations was obtained. Thereafter, based on this validation, 3C- and 4H-SiC vertical power diodes are assessed to create trade-off maps. Depending on the operation requirements imposed by the application, the developed tradeoff maps set the boundary of the realm for those two polytypes and allows to predict which applications would benefit once electrically graded 3C-SiC becomes available.