Comparison of New Octagonal Cell Topology for 1.2 kV 4H-SiC JBSFETs with Linear and Hexagonal Topologies: Analysis and Experimental Results

This paper compares experimentally obtained electrical characteristics of a novel Octagonal (Oct) cell topology for 1.2 kV-rated 4H-SiC JBSFETs with the Linear and Hexagonal (Hex) cell topologies for the first time. The various cell topologies were fabricated using the same process flow at a 6-inch foundry. The third quadrant on-state voltage drop for the JBS diode in the Oct JBSFET was matched with the Linear cell design by using adequate JBS diode area within the cell. Experimental results demonstrate that the Oct JBSFET has 1.7× and 2.2× better HF-FOM [ Ron×Qgd] compared with the Linear and Hex cell JBSFETs, respectively. In addition, the Oct JBSFETs have a much superior [C_iss/C_rss] ratio to suppress shoot through currents during high frequency switching.