Comparison of Commercial Planar and Trench SiC MOSFETs by Electrical Characterization of Performance-Degrading Near-Interface Traps

The suboptimal performance and low channel-carrier mobility of silicon carbide (SiC) power MOSFETs are attributed to a high density of oxide traps near the 4H-SiC/SiO _{\text{2}} interface. In this article, a commercial 1200-V SiC trench MOSFET has been compared with a planar MOSFET obtained from the same manufacturer. We employed a newly developed integrated-charge method to quantify the near-interface traps (NITs). The results reveal that, at operating gate voltages, 15% of the total channel electrons were trapped for longer than 500 ns in the planar MOSFET compared to 9% in the trench MOSFET.