Predictive Atomistic and Coarse-Grained Modeling of Epitaxial Thin Film Growth
Thin film deposition provides a pathway to create a variety of complex surface nanostructures with diverse functionality. Atomistic modeling of homoepitaxial film growth (A on A) on single-crystal surfaces, when combined with kinetic Monte Carlo (KMC) simulation, has achieved remarkable predictive accuracy in describing far-from-equilibrium evolution*. This includes both initial submonolayer 2D island formation and subsequent multilayer growth and kinetic roughening (i.e., formation of 3D mound-like stacks of 2D islands). Less progress has been made for heteroepitaxy on single-element substrates (A on B) or on alloys (A on BC), where strain and quantum size effects can be significant. As an alternative to atomistic treatments, coarse-grained modeling is appealing from the perspective of algorithmic efficiency, and also to provide deeper insight into fundamental issues such as development 2D island distributions or 3D mound coarsening dynamics. We review recent successes and open challenges for modeling. *Evans et al., Surf. Sci. Rep. 61 (2006) 1-128.
Jim Evans, Ames Laboratory USDOE and Iowa State University