Incomplete melting of the Si(100) surface from molecular-dynamics simulations using the effective-medium tight-binding model

We present molecular dynamics simulations of the Si(100) surface in the temperature range 1100-1750 K. To describe the total energy and forces we use the effective-medium tight-binding model. The defect-free surface is found to melt at the bulk melting point which we determine to be 1650 K, but for a surface with dimer vacancies we find a pre-melting of the first two layers 100 K below the melting point. We show that these findings can rationalize recent experimental studies of the high-temperature Si(100) surface.