Fast multiscale kinetic Monte Carlo simulations of three-dimensional self-assembled quantum dot islands

作者：Zhu R^*; Pan E; Chung P W

来源：Physical Review B, 2007, 75(20): 205339.

DOI：10.1103/PhysRevB.75.205339

A three-dimensional kinetic Monte Carlo model is developed to simulate the growth of self-assembled quantum dot islands. Our multiscale model includes the long-range strain energy contribution from a fast continuum Green's function calculation and an up-down ratio describing the relative probability for atoms to jump out of the plane of the surface during the growth process. For the model material InAs/GaAs(001), we studied the effect of the flux rate and the deposition and interruption times on the island shape and ordering, which shows that a lower flux rate and a longer growth time correspond to a better island distribution. We also successfully simulated the relation between the island height and the up-down ratio. It is observed that for an up-down ratio between 1 and 20, the island height increases dramatically with increasing up-down ratio, reaching an inflection point around 13. When the up-down ratio continues to increase from 20, the island height approaches a constant value at about 20 grids. The critical up-down ratio 13 signifies the transition from a flat cluster growth mode to a sharp three-dimensional island growth mode.

• 出版日期2007-5