Experimental Demonstration and Analysis of 4.5kV Bidirectional Superjunction Power DMOSFETs in 4H-SiC

We have experimentally demonstrated two configurations for a 4.5kV 4H-SiC bidirectional (BD) Superjunction (SJ) power DMOSFET for the first time, using two unidirectional (UD) General Electric (GE) 4.5kV 4H-SiC SJ DMOSFETs. The measured RON,sp of BD SJ in Common-Drain (CD) and Common-Source (CS) configuration is 20 and 21 mΩ.cm2 at room temperature, respectively. These values are approximately 28% and 49% lower than those of the estimated Charge-balanced (CB) and Conventional (Conv.) BD MOSFETs of the same voltage rating. The measured room temperature total switching energy losses (Eswitch) per cycle for UD, BD CD, and BD CS SJ are 4.1, 3.9, and 5.4 mJ/cm2, respectively. CD configuration achieves better overall performance than CS configuration. It also shows an 8-fold decrease in total specific power losses compared to the 3.3kV BD CD CB DMOSFET at 2 kHz, with better performance from 100Hz to 100kHz.