Atomic-scale Monte Carlo study of GaAs(0 0 1)-(2 × 4) growth on vicinal surfaces

The step-flow growth modes on a GaAs(0 0 1)-β2(2×4) surface in molecular-beam homoepitaxy are studied by kinetic Monte Carlo simulations. Our results show that a terrace edge parallel to the [1̄ 1 0] direction (A step) does not grow in a coherent manner but by the growth of the rather short segments of As dimer rows. Moreover, the growth morphology of a terrace edge perpendicular to this direction (B step) is found to depend on the relative phase of the β2(2×4) structure between an upper terrace and a lower one. We conclude that a surface with B steps grows more smoothly than that with A steps.