Vertically Self-Organized InAs Quantum Box Islands on GaAs(100)

Coherent InAs islands separated by GaAs spacer layers are shown to exhibit self-organized growth along the vertical (i.e., growth) direction. The driving force for such vertically self-organized growth is shown to be the interacting strain fields induced by the islands which give rise to a preferred direction for In migration. A model analysis accounting for the mechanochemical surface diffusion gives an island average size and average separation dependent characteristic spacer layer thickness $z_0$ below which a vertically self-organized growth occurs.