Step motion mediated morphology evolution of patterned vicinal Si(111) surface during high temperature annealing*

We present the results of numerical simulations of the evolution of vicinal Si(111) surfaces which have been patterned with arrays of cylindrical pits, during high temperature annealing. The initial morphology consists of linear steps due to the vicinality, and loop steps due to the patterning, whose spacing varies locally and evolves with time. We use a mesoscopic model to describe the motion of individual steps under the effects of sublimation, step stiffness (line tension), and step-step interaction. A comparison with experimental observations [1] demonstrates that the step-step interaction plays a crucial role in the evolution of the surface morphology, and suggests that it changes sign, becoming attractive between "up" steps and "down" steps. *Work supported by the Laboratory for Physical Sciences and an NSF-MRSEC [1] T. Kwon, H.-C. Kan and R.J. Phaneuf, in this section.