CHEMISTRY, MICROSTRUCTURE, AND ELECTRICAL-PROPERTIES AT INTERFACES BETWEEN THIN-FILMS OF COBALT AND ALPHA-(6H) SILICON CARBIDE-(0001)

Thin films (4 - 1000 angstrom) of Co were deposited onto n-type 6H-SiC(0001) wafers by UHV electron beam evaporation. The chemistry, microstructure, and electrical properties were determined using x-ray photoelectron spectroscopy, high resolution transmission electron microscopy, and I-V and C-V measurements, respectively. The as-deposited contacts exhibited excellent rectifying behavior with low ideality factors and leakage currents of n < 1.06 and 2.0 x 10(-8) A/cm2 at - 10 V, respectively. During annealing at 1000-degrees-C for 2 min, significant reaction occurred resulting in the formation of CoSi and graphite. These annealed contacts exhibited ohmic-like character, which is believed to be due to defects created in the interface region.