Coexistence of meandering and bunching of steps on vicinal surfaces

Abstract

We simulate morphology and its evolution of vicinal surfaces in epitaxy by using the phase-field model. For usual parameters of Cu vicinal surfaces, a pure in-phase meandering pattern consistent to the experimental images is obtained. Nevertheless, vicinal surfaces grow into more complex hierarchy for a small kink energy. In addition to step meandering, step bunching happens due to competition of local step fluctuation and interlayer Ehrlich-Schwoebel barrier in the presence of the step meandering. This implies that step meandering and step bunching can coexist in some growing epitaxial vicinal surfaces.