Interfacial reactions of Ni/Si0.76Ge0.24 and Ni/Si1-x-yGexCy by vacuum annealing and pulsed KrF laser annealing were studied. Upon annealing at a temperature of 200-600 degrees C Ge segregation occurred with the extent becoming more severe at higher temperatures. The temperatures at which phase transformation and the agglomeration structure occurred were higher for Ni/Si1-x-yGexCy than for Ni/Si0.76Ge0.24. Upon pulsed KrF laser annealing the agglomeration structure was considerably improved, however, the retardation of phase transformation in the Ni/Si1-x-yGexCy system still occurred. C accumulation around the original amorphous/crystal interface formed by Cf implantation played a significant effect on delaying the phase transformation. For the Ni/Si0.76Ge0.24 and Ni/Si1-x-yGexCy samples annealed at 0.2 J/cm(2) for 20 and 30 pulses, respectively, smooth Ni(Si0.76Ge0.24)(2) and Ni(Si1-x-yGexCy)(2) films could be grown, meanwhile Ge segregation and strain relaxation of the unreacted Si0.76Ge0.23 films were effectively suppressed.