Effects of Strain on Island Morphology and Size Distribution in Irreversible Submonolayer Growth

The effects of strain on the island-morphology and size-distribution in irreversible submonolayer growth with rapid island relaxation are investigated. In our simulations the strain energy is approximated by an isotropic 1/r interaction. While the island density increases with strain, in the presence of sufficient island relaxation due to edge-diffusion, the island-shape changes from square to rectangular. However, due to fluctuations, there is a broad distribution of island-widths. General scaling forms for the island-width and island-length distributions are derived and good scaling is obtained as a function of coverage while there is only a relatively weak dependence on the strain. The scaled island-size distribution is also found to be only weakly affected by strain. These latter results are in qualitative agreement with recent experimental results for InAs/GaAs(100) growth.