集成异质结二极管的4H-SiC半超结MOSFETOA

A novel superjunction MOSFET with an integrated heterojunction diode(SJH-MOSFET)was proposed to enhance the reverse recovery performance of the body diode and reduce switching losses in silicon carbide(SiC)superjunction MOSFETs.The structure incorporated a source-shorted P+polysilicon at the trench bottom,which formed a heterojunction with the 4H-SiC drift region to function as the body diode.In addition,a P+shielding layer and a semi-superjunction design were incorporated to optimize the electric field distribution.TCAD simulations comparing the proposed device with a conventional double-trench MOSFET demonstrated that it achieved a breakdown voltage of 1710 V and a specific on-resistance of 1.45 mΩ·cm2,corresponding to an 18.4％increase in breakdown voltage and a 12.1％reduction in specific on-resistance,respectively.The heterojunction diode effectively suppressed minority carrier injection,reducing the reverse recovery charge by 60.9％.By shrinking the effective gate-drain coupling area,the proposed device reduced the Miller plateau charge by 79.2％,resulting in a 40.4％reduction in total switching loss.This work provides a viable design route for high-performance SiC power devices that simultaneously improve dynamic performance and reliability.