Abstract
The total energies for the shape transition processes between symmetric and asymmetric structures in epitaxial three-dimensional strained islands are discussed here. For structures that allow height to increase simultaneously with width and length during growth, the shapes formed should be symmetric or transform from asymmetric to symmetric; for truncated-hut structures with fixed heights smaller than a critical value, the shapes formed should be asymmetric or transform from symmetric to asymmetric. The relation between the shape transition processes and the systematic conditions obtained here can be used to anticipate whether the elongated epitaxial structures are driven energetically or kinetically. © 2008 American Institute of Physics.