Surface diffusion of metal atoms on polymer substrates during physical vapour deposition

The surface diffusion of physical-vapour-deposited metal atoms on thermopla stic polymer substrates was investigated. In accordance with the hypothesis of the "classical" atomistic diffusion model, diffusion coefficients are d erived from a Monte Carlo simulation. Because the "classical" atomistic dif fusion model neglects the desorption of the metal atoms, the absolute diffu sion data obtained in our investigations should only be considered as rough estimates. It is more the intention of our work to present relative values in order to correlate the metal surface diffusion on polymer substrates wi th their physical states (morphologies and surface dynamics). As expected, the diffusivity of metal atoms is strongly influenced by the chemical affin ity ("reactivity") between the metal atoms and the polymer substrate. Furth ermore, the diffusivity strongly depends on the physical State of the polym er substrate. On polymer surfaces above the glass-transition temperature th e surface diffusivity of metal atoms is 1 order of magnitude higher than th e diffusivity below the grass-transition temperature.