Kinetic Monte Carlo simulations of the growth of silicon germanium pyramids

Abstract

We investigate the nucleation and growth of anisotropic and strained quantum dots in heteroepitaxy by means of kinetic Monte Carlo simulations. Surface energy anisotropy is introduced in order to depict Ge-like dots with (105) facets growing on a Si (100) substrate. Three dimensional islands, mainly in the form of square-base pyramids, are reported and their coarsening is found to be interrupted during annealing. The resulting island density follows the scaling law $\ensuremath{\rho}\ensuremath{\sim}{(D/F)}^{\ensuremath{-}\ensuremath{\alpha}}$ with $\ensuremath{\alpha}\ensuremath{\simeq}0.6$ as a function of the diffusion $D$ to flux $F$ ratio. The island size distribution follows the scaling law resulting from the assumption of a single length scale.