Surface melting of vicinal Si(111) surfaces

Abstract

We study the surface melting of vicinal Si(111) surfaces by means of the Monte Carlo simulation using empirical Tersoff–Dodson potential. The dependence of the atomic structures and the atomic dynamics on the temperature, the adatom coverage and the vicinal angle were calculated. Surface melting occurred on Si(111) vicinal surfaces without Si adatom coverage, while surface melting on flat Si(111) surfaces occurred only with Si adatoms higher than the critical coverage. The melting behavior on vicinal surfaces was quite different, with or without Si adatom coverage. Without Si adatom coverage, surface melting started from the upper terraces of step edges after a finite annealing time. With Si adatom coverage, the melting evolved homogeneously from the top layer in proportion to the annealing time. As the vicinal angle increases, the critical temperature of surface melting lowers. In the lateral distribution function of the melting layers, only the nearest-neighbor correlation is kept and the farther distance correlation is lost. Si atoms in the melting layers move about along the surface with a diffusion coefficient irrespective of the adatom coverage.