title: Island-dynamics model for mound formation: effect of a step-edge barrier.
abstract: We formulate and implement a generalized island-dynamics model of epitaxial growth based on the level-set technique to include the effect of an additional energy barrier for the attachment and detachment of atoms at step edges. For this purpose, we invoke a mixed, Robin-type, boundary condition for the flux of adsorbed atoms (adatoms) at each step edge. In addition, we provide an analytic expression for the requisite equilibrium adatom concentration at the island boundary. The only inputs are atomistic kinetic rates. We present a numerical scheme for solving the adatom diffusion equation with such a mixed boundary condition. Our simulation results demonstrate that mounds form when the step-edge barrier is included, and that these mounds steepen as the step-edge barrier increases.
authors.affiliation: Department of Mathematics, University of California, Los Angeles, California 90095, USA.
authors.forename: Joe
authors.initials: J
authors.lastname: Papac
authors.affiliation: Department of Mathematics, and Institute for Physical Science and Technology, and Center for Scientific Computation and Mathematical Modeling, University of Maryland, College Park, Maryland 20742, USA.
authors.forename: Dionisios
authors.initials: D
authors.lastname: Margetis
authors.affiliation: Department of Mechanical Engineering and Department of Computer Science and Department of Mathematics, University of California, Santa Barbara, California 93106, USA.
authors.forename: Frederic
authors.initials: F
authors.lastname: Gibou
authors.affiliation: Department of Mathematics and Institute for Pure and Applied Mathematics, University of California, Los Angeles, California 90095, USA.
authors.forename: Christian
authors.initials: C
authors.lastname: Ratsch
mesh_terms: D003198:Computer Simulation; D004058:Diffusion; D007700:Kinetics; D008962:Models, Theoretical; D009038:Motion