High current capability of 3C-SiC vertical DMOSFETs

Abstract

Vertical power DMOSFETs in 3C-SiC, ranging in size from a single-cell to 3 × 3 mm 2 containing 12,000 hexagonal cells, were developed for the first time. Both the drain and leakage currents scale linearly with device size up to a 1 × 1 mm 2 device containing 976 cells. An inversion channel mobility of 40 cm 2/V · s and interface state density of 5 × 10 12 to 1 × 10 13 cm −2 eV −1 were obtained. A fabricated DMOSFET with a gate length of 2 μm had a low specific on-resistance of 5.6 mΩ · cm 2 for a single-cell device. A current density of 1220 A/cm 2 for a single-cell device, and 380 A/cm 2 for a 102-cell device were demonstrated. A high current capability of 41 to 132 A at 600 V can be extrapolated for a 3 × 3 mm 2 chip.