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

The temperature dependence of morphology of InAs islands on Si grown throug h Stranski-Krastanow mode is investigated by atomic force microscopy. Forma tion of islands in the range of 15-50 nm is observed for depositions at var ious temperatures for the same monolayer coverage. Growth temperatures betw een 400 and 425 degrees C are found to yield dense ensembles of islands wit h uniform dimensional distributions. Found to exhibit long-term stability, these islands undergo morphological transformation when annealed at tempera tures above 700 degrees C. Ostwald ripening occurs in these islands through an enhanced surface diffusion mechanism at high annealing temperatures. Th e results of annealing experiments indicate surface diffusion being the dom inant mechanism responsible for morphological changes in these island struc tures rather than the heterointerface diffusion. (C) 1999 American Institut e of Physics. [S0003-6951(99)02635-2].