SUBSTRATE INHOMOGENEITY AND THE GROWTH-MORPHOLOGY OF THIN-FILMS

We give a theoretical argument which indicates that the combined effec t of substrate inhomogeneity and grain boundaries can be very importan t in determining the growth morphology of thin metal films on non-wett ing substrates. An elongated metal island on a smooth non-wetting subs trate, with a single grain boundary at its center, is shown to be in a state of unstable equilibrium. Any substrate inhomogeneity is then ab le to pin the island in a metastable state. An estimate of the depinni ng temperature is also given.