Analysis and Experimental Quantification of 1.2-kV 4H-SiC Split-Gate Octagonal MOSFET

A 1.2-kV rated 4H-SiC split-gate octagonal cell MOSFET (SG-OCTFET) is proposed and successfully fabricated in a 6-in foundry for the first time. The measured results quantify the benefits of the SG-OCTFET structure: improvement in high-frequency figures of merit (HF-FOM) (R-ON x C-gd) by 1.8x, HF-FOM (R-ON x Q(gd)) by 1.6x, and FOM (C-iss/C-gd) by 1.6x compared with the optimized compact OCTFET design due to the reduced gate-to-drain overlap area. An important conclusion of this letter is that unlike commercially available 1.2-kV SiC power MOSFETs with linear cell topology, the 1.2-kV SG-OCTFET design can outperform commercially available 600-V Si super-junction devices.