Large Area Silicon Carbide Vertical Junction Field Effect Transistors for High Temperature Power Conditioning Applications

SiC VJFETs are excellent candidates for reliable high power/temperature switching as they only use PN junctions in the active device area where the high electric fields occur. VJFETs do not suffer from forward voltage degradation, exhibit excellent short circuit performance, and operate at 300degC. 0.19 cm² 1200 V normally-on and 0.15 cm² low-voltage normally- off VJFETs were fabricated. The 1200 V VJFET outputs 53 A with a forward drain voltage drop of 2 V and a low specific on-state resistance of 5.6 mOmega cm². The low-voltage VJFET outputs 38 A with a forward drain voltage drop of 3 V and a specific on- state resistance of 10 mOmega cm². The 1200 V SiC VJFET was connected in the cascode configuration with a Si MOSFET and with a low-voltage SiC VJFET to form normally-off power switches. At a forward drain voltage drop of 2 V, the SiC/MOSFET cascode switch outputs 31 A and the all-SiC cascode switch outputs 19 A.