Annealing effects on the interfacial reactions of Ni on Si0.76Ge0.24 and Si1−x−yGexCy

Abstract

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 °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 C+ 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/cm2 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 Si0.76Ge0.24 films were effectively suppressed.