Reconstruction of Si(001) and adsorption of Si adatoms and ad-dimers on the surface: Many-body potential calculations

Abstract

A recently developed potential function for covalent materials [Phys. Status Solidi B 212, 9 (1999)] is used to simulate the reconstruction of the Si(001) surface, the surface adsorption, and diffusion of Si on the surface. For the simulation of reconstruction of Si(001) surface, our numerical results show that an empirical potential can correctly predict buckling-dimerized asymmetrical (001)-(2×1), p-(2 × 2), and c-(4 × 2) configurations and the relative stability between them in energetics. For the calculations of surface adsorption, we consider the formation energies and diffusion activation energies of several possible binding sites. The predicted stable and metastable configurations and diffusion paths of Si adatom and Si ad-dimers on the Si(001)-(2 × 1) surface are in agreement with those from first-principles calculations and experiments.