A potential energy scaling Monte Carlo simulation of thin film nucleation and growth

Abstract

A Monte Carlo computer simulation employing a potential energy scaling technique has been used to model the initial stages of thin film growth. The model monitors variations in the interaction potential that occur as a result of the arrival or departure of adatoms or impurities at sites in a 20 x 20 array. Boltzmann-ordered statistics are used to simulate fluctuations in vibrational energy at each site in the array, and the resulting site energy is compared with threshold levels of possible atomic events. In addition to adsorption, desorption and surface migration of adatoms, the simulation considers adatom incorporation and diffusion of a substrate atom to the surface. The effect of lateral interaction of nearest, second-nearest and third-nearest neighbors is also considered. A series of computer experiments were conducted for the Ge-Fe(100) system to illustrate the behavior of the model and to show that the surface migration of monomers, the formation of multiatom clusters and the coalescence of growing clusters behave in an accurate physical manner. Further, the model was found to be especially useful in the study of growth around different types of surface defects.