Study of the geometrical parameters of In nanostructures during droplet epitaxy on the As-stabilized GaAs(001) surface

Abstract

The droplet epitaxy of indium on the As-stabilized GaAs(001) surface is investigated using theoretical model and experimental studies. The model is developed on the basis of a combination of the nucleation thermodynamic theory and kinetic Monte Carlo algorithm. The surface density of droplets is observed to decrease with increasing temperature whereas both the droplet diameter and height increases because of the intensive attachment of In adatoms to larger, i.e. more stable, islands. At the same time, the droplet aspect ratio demonstrates a nonmonotonic temperature dependence. Although a general tendency for the aspect ratio with increasing temperature is falling, there is a temperature at which the aspect ratio is maximal both for simulations and experiments. This is caused by the temperature balancing between the wetting of the substrate and the formation of islands with near-spherical shape. The simulation results are in good agreement with obtained experimental data in a wide range of substrate temperatures.