Journal of Materials Research


Chemistry, microstructure, and electrical properties at interfaces between thin films of cobalt and alpha (6H) silicon carbide (0001)

L.M. Portera1, R.F. Davisa1, J.S. Bowa2, M.J. Kima2 and R.W. Carpentera2

a1 Department-of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695-7907

a2 Center for Solid State Science, Arizona State University, Tempe, Arizona 85287-1704


Thin films (4–1000 Å) 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 × 10−8 A/cm2 at −10 V, respectively. During annealing at 1000 °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.

(Received June 01 1994)

(Accepted September 27 1994)