Morphological transition of Sn particles on Si substrate induced by ion irradiation

The effect of ion irradiation on cluster-like Sn films grown on a crystalline Si substrate was studied by scanning electron microscopy (SEM) and Rutherford backscattering spectrometry combined with channelling (RBS/C). It was established from SEM observations that ion-beam irradiation causes a morphological change in the cluster-like Sn films; the Sn particles wet the substrate and coalesce on ion irradiation. In order to characterize the Sn/Si interface, RBS/C measurements were performed to investigate the correlation between the Sn/Si interfacial structure and the morphology of the Sn film on the Si substrate. It was revealed that intermixing between the Sn film and the substrate and the segregation of Si atoms may be responsible for the reduction in the interfacial and surface free energies respectively, which results in the morphological transition from a three-dimensional cluster-like film to a uniform film.