Demonstrating the potential of 6-H silicon carbide for power devices

Abstract

Discusses the first vertical UMOS power MOSFETs ever reported in SiC, shows the highest gain 6H-SiC BJTs (bipolar junction transistors) and thyristors ever reported, and demonstrate the high-temperature operation of these devices. Vertical power MOSFETs fabricated in 6H-SiC with a UMOS design have specific on-resistances as low as 38 m Omega -cm/sup 2/ at a gate bias of +12 V. These devices can have current densities as high as 190 A/cm/sup 2/ (0.32 A/cm of gate periphery) and can dissipate a maximum power density of 5.4 kW/cm/sup 2/. SiC BJTs have been demonstrated up to 400 degrees C. The device structure used a reactive ion etched emitter with sintered Ni contacts to both the emitter and collector, and Al/Ti alloy contacts to the base. Four-layer structures have also been demonstrated in 6H-SiC, with p-n-p-n thyristors showing 100 V operation.