4H-SiC Double RESURF MOSFETs with a Record Performance by Increasing RESURF Dose

For further improvement of lateral power devices, 4H-SiC double RESURF MOSFETs with high RESURF doses have been fabricated and characterized. The drift resistance was decreased and the breakdown voltage was increased with increasing RESURF doses, although oxide brekaodown occurs when the RESURF doses are too high. The increase in drift resistance at elevated temperature was smaller for double RESURF MOSFETs than 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 1430 V and an on-resistance (R_ON) of 57 mOmegacm², and the MOSFETs on 4H-SiC (0001 macr) face demonstrated a higher breakdown voltage of 1550 V and a lower on-resistance of 54 2 2 / mOmegacm² . The figure-of-merit (V_B /R_ON) of the fabricated device on Si face and C face is 36 MW/cm2 and 44 MW/cm², respectively, which is the highest value among any lateral MOSFETs ever reported.