Chemical potential maps and spatial correlations in 2D-island ripening on Si(001)

We have used low energy electron microscopy to study the roles of surface diffusion and step-edge attachment kinetics in 2D-island ripening, a phenomenon closely related to epitaxial growth. From experimental maps of the chemical potential, showing variations of up to a factor of 3, we conclude that nearest-neighbor correlations between islands are of central importance, in contrast to common mean-field theory. Detailed simulations of the time evolution of specific island configurations are in close agreement with experimental results. © 1995 The American Physical Society.