A multi phase-field model is developed to investigate the effect of interface energy between a film and substrate on the morphological evolution of the film during self-assembled quantum dot (QD) growth in the deposition process. The single- and multi-island growth simulations for the SiGe/Si system are carried out in two-dimensional space with various interface energies. From the numerical results, it is clarified that the island shape and the island morphological transition points dramatic change depending on the magnitude of the interface energy. Here, the transition points, such as that from a pyramid to a dome, occurred in an earlier growth stage with higher interface energy. It is also observed that high interface energy results in large island size fluctuation. (C) 2007 Elsevier B.V. All rights reserved.