Optimization of Surface Layers for Suppression of Agglomeration in Ag Films

We previously reported that Al, Ti, and Nb surface layers can effectively suppress agglomeration in Ag films, which is dominated by the surface diffusion of Ag atoms. In this study, Ag films with Pd, Ni, and W surface layers were prepared by RF magnetron sputtering, and the properties of these films were compared with previous observations of the effects of Ti and Nb surface layers. The most important properties of the appropriate surface layers for the suppression of agglomeration in Ag films are a high cohesive energy or a high Gibbs free energy of formation of the oxide, and a low solid solubility in Ag