The Si(100) surface is known to be reconstructed due to the formation of dimer rows. Recent temperature-programmed experiments on H desorption from this surface had indicated that adsorbate-adsorbate lateral interactions in dimers were attractive and very strong (-6kcal/mol). By using the lattice-gas model, a study was made here of the effect of this interaction upon the coverage dependence of the chemical diffusion coefficients for jumps of H atoms along, and perpendicular, to dimer rows. The adsorbate-adsorbate lateral interaction in the activated state was also taken into account. It was found that, for reasonable values of the parameters, both diffusion coefficients decreased with increasing coverage. The anisotropy in the coverage dependence of the diffusion coefficients was expected to be rather weak.

V.P.Zhdanov: Physical Review B, 1993, 48[19], 14325-30