Effects of strain on island scaling studied by Monte Carlo simulations

Abstract

Strained heteroepitaxial growth is a possible means of obtaining carrier confinement in reduced-dimensional systems for applications in optoelectronic devices. The epitaxial growth of InAs on GaAs provides an excellent prototypical system due to the significant lattice mismatch of approximately 7% between the two constituents. At submonolayer coverages, highly elongated two-dimensional InAs islands were observed experimentally with a preferred width of approximately 4 nm. When the island size distributions were separated into [110] and [1̄10] components, scaling was only observed in the [1̄10] direction, and clustering was observed in the radial separation distribution. We have used lattice gas Monte Carlo simulations to explore the effects of intrinsic system anisotropies and strain on island scaling. We found that the experimentally observed scaling behavior can only be explained by taking into consideration both the system anisotropies and strain.