Improved Performance of 4H-SiC Double Reduced Surface Field Metal–Oxide–Semiconductor Field-Effect Transistors by Increasing RESURF Doses

For further improvement of lateral power devices, 4H-SiC double reduced surface field (RESURF) metal–oxide–semiconductor field-effect transistors (MOSFETs) with high doses in RESURF region have been fabricated and characterized. The drift resistance was decreased and the breakdown voltage was increased with increasing RESURF doses, although breakdown occurs in the oxide when the RESURF doses are too high. The increase of drift resistance in double RESURF MOSFETs at elevated temperature was smaller than that in single RESURF MOSFETs, due to the higher doping concentration in the RESURF region. The fabricated 4H-SiC(0001) double RESURF MOSFETs exhibited a breakdown voltage ( V B ) of 1540 V and an on-resistance ( R ON ) of 55 mΩ cm 2 . The figure-of-merit ( V B 2 / R ON ) of the fabricated device is 43 MW/cm 2 , which is the highest value compared with those reported in lateral MOSFETs.