Roughening in Nonlinear Surface Growth Model

The aim of this paper is to examine the coarsening process in the evolution of the surface morphology during molecular beam epitaxy (MBE). A numerical approach for modeling the evolution of surface roughening in film growth by MBE is proposed. The model is based on the nonlinear differential equations by Kuramoto–Sivashinsky (KS) namely, KS and CKS (conserved KS). In particular, we propose a “combined version” of KS and CKS equations, which is solved as a function of a parameter r for the 1 + 1 dimensional case. The computation provides film height as a function of space and time. From this quantity the change of the width of the film over time has numerically been studied as a function of r. The main result of the research is that the surface width is exponentially increasing with increasing time and the change in surface width for smaller r values is significantly greater over longer time interval.