Comparative Performance Evaluation of High-Voltage Bidirectional, Conventional and Superjunction Planar DMOSFETs in 4H-SiC

Abstract

We quantitively compare the static and dynamic performance for high-voltage SiC bidirectional (BD) conventional and superjunction (SJ) DMOSFETs by using 3D TCAD simulations. We extract the specific on-resistance (RON,sp) and the total specific switching charge (QT,sp), which is a sum of the specific gate charge (QG,sp) and drain charge (QDS,sp) to quantify both the static and switching characteristics respectively. We also develop a new Figure-of-Merit (FoM), which is the product of RON,sp . QT,sp, to evaluate the overall performance. We show that the high-voltage 4H-SiC BD SJ DMOSFET has the best FoM with substantial (>58%) improvement, compared to the BD conventional DMOSFETs, which increases with increasing breakdown voltage.