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

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 (R ON,sp ) and the total specific switching charge (Q T,sp ), which is a sum of the specific gate charge (Q G,sp ) and drain charge (Q DS,sp ) to quantify both the static and switching characteristics respectively. We also develop a new Figure-of-Merit (FoM), which is the product of R ON,sp . Q T,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.