Abstract
Pure Ag, Cu, Ni, and Co films were prepared by vacuum evaporation on a LiNbO3 single-crystal substrate excited by surface acoustic waves (SAW) at 45 MHz under various amplitude conditions. The surface morphology of the films and the SAW propagation properties during deposition were investigated in order to determine the influence of SAW excitation on the structural changes in the films. In the Ag and Cu films, the surface roughness Ra and the thickness dp at which the SAW attenuation reached a maximum changed drastically as a function of the SAW amplitude, in contrast to the case for the Ni and Co films. Taking into account that dp corresponds to the thickness at which the film structure changes from island to continuous, it was considered that SAW influences the initial stage of film growth and that a large SAW amplitude enhances the agglomeration of islands. By in situ monitoring of the propagation properties of SAW, microscopic structural changes were also found in the Ag and Cu films during the initial growth stage.
