Breakthrough in trade-off between threshold voltage and specific on-resistance of SiC-MOSFETs

The threshold voltage of 4H-SiC MOSFET increases drastically by performing wet oxidation after nitridation of gate oxide without significant decrease in the channel effective mobility. The increment of the threshold voltage depends on the wet oxidation conditions, and wet oxidation improves the trade-off between the threshold voltage and the specific on-resistance. We fabricated 600 V 4H-SiC MOSFETs with a threshold voltage of 5.11 V and a specific on-resistance of 5.2 mΩcm² using the procedure above. The stability of the threshold voltage for the SiC-MOSFETs was confirmed by a HTGB test.