MORPHOLOGICAL STABILITY OF ISLANDS UPON THIN-FILM CONDENSATION

The stability of shape of a disklike cluster growing on a substrate fr om supersaturated vapor of adsorbed particles is studied. The investig ation is carried out by expansion in terms of cosines of a minor defle ction of island shape from a disk and subsequent evaluation of expansi on coefficient relations in time. In addition to diffusion of adatoms towards an island and the relation between an equilibrium concentratio n and curvature, some kinetic phenomena on the surface of an island, t he interface energy anisotropy, and surface diffusion are taken into a ccount. It is shown that the reevaporation process of adatoms from a s ubstrate leads to a considerable change in the criteria of instability initiation of the island shape as compared to the three-dimensional c ase. The mode with number nu starts to be excited only in the case whe re the radius of a cluster lies within a certain interval, R(1)(nu) < R < R(2)(nu). The criterion of island faceting is derived as well.