Demonstration of High Voltage (15kV) Split-Gate 4H-SiC MOSFETs

In this work, 15 kV 4H-SiC Split-Gate Vertical Planar MOSFETs (SG-MOSFET) are demonstrated for the first time. Both the traditional MOSFET and SG-MOSFET were fabricated on the same 6-inch SiC wafer and achieved maximum breakdown voltages (BV) of 15930 V and 15080 V, respectively. This is the first demonstration of the split gate architecture on SiC for voltage ratings above 10 kV, and this BV was achieved using a Hybrid-Junction Termination Extension (JTE) edge termination. The fabricated SG-MOSFETs showed a reduction in gate charge as well as no significant deviation in forward conduction and blocking behavior when compared to their MOSFET counterparts. These results display the SG-MOSFET’s potential for lower switching power losses in ultra-high voltage devices without compromising device static performance. In the following text, the layout, static performance, and gate charge of the MOSFET and SG-MOSFET are described to show the exciting potential of the high voltage SG-MOSFET.