Thermal stability of WSi_X Schottky contacts on n-type 4H-SiC

Sputter-deposited WSi_0.45 rectifying contacts were characterized on n-type 4H-SiC as a function of annealing and measuremental temperature. The as-deposited contacts show evidence of recombination-dominated carrier transport and a high series resistance due to ion-induced damage occurring during the Ar plasma-assisted deposition. Annealing at 500 °C for 1 min produced a maximum barrier height of 1.15 eV and reduced the diode ideality factor. The contacts were degraded by annealing at >700 °C but showed reduced forward and reverse currents when measured at elevated temperature (300 °C) compared to the more common Ni rectifying contacts.