Nucleation of Vapor Deposits

Abstract

The size of the critical nucleus in the formation of metal deposits from the vapor is very small, probably containing 10 atoms or less. For nuclei of this magnitude the uncertainties concerned with the liquid-drop model and the concept of surface energy in the Volmer and Weber and Becker and Doring treatment of nucleation become serious. An expression for the density of clusters of atoms is developed using statistical mechanics. From this an expression for the nucleation rate is derived on a kinetic basis. It is also observed that certain orientation effects in the deposit can be explained if the small size of the critical nucleus is taken into account.