Formation of metal–polymer interfaces by metal evaporation: influence of deposition parameters and defects

Metal–polymer interfaces with different but well defined morphologies were prepared by evaporating noble metals (Au, Ag, Cu) onto chemically different polymers, i.e. bisphenol-trimethyl cyclohexane polycarbonate (TMC-PC), pyromellitic dianhydride-oxydianiline (PMDA-ODA) polyimide (PI), polystyrene (PS) and the low-k dielectric Teflon AF 1601. The interfaces were characterised using transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). The combination of these techniques allowed one to determine morphological parameters such as concentration and distribution of metal clusters at the surface and in the near-surface region. In addition, radiotracer measurements yielded exact metal condensation coefficients C and was used to determine the extent of diffusion of metal atoms into the polymers. First experiments on the macroscopic adhesion of Cu on TMC-PC showed that the initially low peel strength can be increased substantially by subsequent annealing above the polymer glass transition temperature, T_g.