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

摘要

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 breakdown 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{sub}B) of 1430 V and an on-resistance (R{sub}(ON)) of 57 mΩcm{sup}2, and the MOSFETs on 4H-SiC (0001) face demonstrated a higher breakdown voltage of 1550 V and a lower on-resistance of 54 mΩcm{sup}2. The figure-of-merit ((V{sub}B){sup}2/R{sub}(ON)) of the fabricated device on Si face and C face is 36 MW/cm{sup}2 and 44 MW/cm{sup}2, respectively, which is the highest value among any lateral MOSFETs ever reported.