6.5-kV Class 4H-SiC Deep Epi-Refilled Super-Junction Schottky Diode With Record Performance Over 7.2 GW/cm 2

This work presents the characteristics of 6.5kV-class 4H-SiC super-junction (SJ) Schottky diodes fabricated by trench etching and epitaxial regrowth approach, forming P-pillars with a length over 40 μm and an aspect ratio above 12. The fabricated SJ device achieves a breakdown voltage (BV) of 7 kV and a specific on-resistance (RON,sp) of 6.8 mΩ·cm², leading to a high power figure-of-merit (BV2/RON,sp) over 7.2 GW/cm². The temperature dependence of RON,spis measured, extracted and modeled, showing superior performance compared to the non-SJ device. Stress tests of 2000 repetitive reverse-sweep cycles and a 10-h constant reverse-bias stress test at 5 kV have been conducted, during which no significant variation in leakage current is observed. Asymmetric blocking characteristic against charge imbalance is observed in the fabricated SJ devices and further analyzed using TCAD simulations. These results demonstrate the strong potential of SJ technology for multi-kilovolt 4H-SiC power devices.