Abstract
Using a mean-field approximation we describe the early stages of growth of Ge on Si(111) mediated by a Pb surfactant. A set of rate equations is constructed for the time evolution of the number of clusters of a given size. The Ge atoms are deposited onto the surface at a constant flux rate, giving rise to a monomer population. The rates of growth and dissociation of the clusters are then calculated assuming that the dissociation energy , where is the energy required to break one bond, and is the diffusion energy of an isolated atom. Finally, is the average number of bonds broken when a cluster reduces its size by 1. This dependence is obtained from a separate kinetic Monte Carlo experiment. The phenomenological constant by assumption. Our mean-field approximation describes the essential experimental results observed in growth.
- Received 9 August 2006
DOI:https://doi.org/10.1103/PhysRevB.75.045410
©2007 American Physical Society