Impact of Reverse Current Spreading on Diode Conduction Reliability Of SBD-Embedded SiC MOSFET with Deep P-Shield Structure

The device structure of SBD-embedded MOSFET was investigated and the complicated tradeoff relationship of on-state resistance, short-circuit ruggedness, and diode conduction capability was improved. TCAD analysis indicated that bipolar conduction in body diode of MOSFET with deep p-shield can be suppressed by developing current spreading layer structure. The fabricated devices demonstrated adequate ruggedness in short-circuit operation and unipolar conduction capability in diode operation while obtaining low on-state resistance. The reduction in leakage by the developed structure enabled drift layer tuning and finally low on-resistance of 2.0 mΩ-cm
²
was demonstrated.