Magic Islands and Barriers to Attachment: A Si/Si(111)7x7 Growth Model

TL;DR

This paper models how activation barriers affect island size distribution and density during homoepitaxial growth on Si(111)7x7 surfaces, revealing 'magic' island sizes and growth rate dependencies.

Contribution

It introduces a growth model that accounts for activation barriers, explaining the emergence of 'magic' island sizes and their behavior during growth and surface equilibration.

Findings

Island size distribution peaks at 'magic' sizes

Island density strongly depends on growth rate

'Magic' islands observed during surface equilibration

Abstract

Surface reconstructions can drastically modify growth kinetics during initial stages of epitaxial growth as well as during the process of surface equilibration after termination of growth. We investigate the effect of activation barriers hindering attachment of material to existing islands on the density and size distribution of islands in a model of homoepitaxial growth on Si(111)7x7 reconstructed surface. An unusual distribution of island sizes peaked around "magic" sizes and a steep dependence of the island density on the growth rate are observed. "Magic" islands (of a different shape as compared to those obtained during growth) are observed also during surface equilibration.