Thickness dependence of the morphology of ultrathin quench condensed gold films

We have studied, using in situ scanning tunneling microscopy, the morphology of ultrathin quench condensed Au films in the thickness range in which they first become electrically continuous. With increasing thickness, the film evolves from a smooth and nearly featureless morphology, to a single layer of nanoclusters, to a loose pack of multiple layers of nanoclusters. This evolution depends only weakly on the substrate material and preparation. We compare our results to previously proposed models of quench condensed film structure.