Molecular dynamics study of adatom diffusion on Si(100) surface — importance of the exchange mechanism

Abstract

The Si adatom diffusion on a Si(100) surface is studied at temperatures between 1000 and 1300 K through long-time-scale empirical molecular dynamics simulations. Exchange is found to occur with a non-negligible frequency, roughly 1 30 to 1 80 as often as hopping occurs. This has only a minor effect on the diffusion constants parallel to the dimer row, but has a major effect on those perpendicular to the dimer row. In the simulations, a variety of complex exchange events involving up to three surface atoms were observed. The dynamical effects are also discussed by comparing with the static calculations.