Ternary silicide Co1-xNixSi2/n-Si(100) contacts with different Ni concentrations were formed by solid phase reaction of Co/Ni bilayer with substrate Si at various annealing temperatures. The Schottky barrier heights, as well as their uniformity, were studied using current-voltage-temperature (I-V T) measurements. A clear trend is found that the barrier height inhomogeneity increases with increasing the annealing temperature. Ni incorporation reduces not only the silicidation temperature, but also the temperature at which the contact becomes inhomogeneous. (C) 2004 Elsevier Ltd. All rights reserved.