Temperature-dependent morphology of three-dimensional InAs islands grown on silicon

The temperature dependence of morphology of InAs islands on Si grown through Stranski–Krastanow mode is investigated by atomic force microscopy. Formation of islands in the range of 15–50 nm is observed for depositions at various temperatures for the same monolayer coverage. Growth temperatures between 400 and 425 °C are found to yield dense ensembles of islands with uniform dimensional distributions. Found to exhibit long-term stability, these islands undergo morphological transformation when annealed at temperatures above 700 °C. Ostwald ripening occurs in these islands through an enhanced surface diffusion mechanism at high annealing temperatures. The results of annealing experiments indicate surface diffusion being the dominant mechanism responsible for morphological changes in these island structures rather than the heterointerface diffusion.