Abstract
The formation of self-assembled heteroepitaxial islands in elastically anisotropic cubic films is investigated by a three-dimensional dynamic method. In the formulation, the {100} film surfaces evolve through surface diffusion driven by the gradient of the surface chemical potential. Our simulations reveal that when the elastic anisotropic strength A [A is defined as 2C(44)/(C-11-C-12), where C-11, C-12, and C-44 are elastic constants] is larger than 1 the formed islands are preferentially aligned along [100] directions, while when A is smaller than 1 the formed islands are preferentially aligned along the [110] directions. It is found that the stronger the elastic anisotropy, the stronger the island self-assembly. In addition, the island alignment and averaged island spacing right after island formation are found to be related to the smallest fastest surface instability wavelength of the elastically anisotropic films.