SCALING OF SUBMONOLAYER Cu ISLANDS GROWN ON Cu(110). D.A. Walko, K.L. Whiteaker, and I.K. Robinson, University of Illinois, Urbana, IL 61801

The structure and properties of a thin film are often determined by the growth conditions as the first monolayer is deposited. We have studied the influence of an anisotropic substrate on the nucleation, growth, and coalescence of homoepitaxial islands. Surface x-ray diffraction was used in situ to study submonolayer deposition of Cu on Cu(110). After deposition, we found diffuse scattering near the out-of-phase condition featuring an elliptical ring, which is due to the anisotropic island morphologies. The major and minor axes of the ellipse are proportional to the island densities (or inversely proportional to the island spacing) in the in-plane [001] and [110] directions respectively. The density of islands in each of these directions scales with deposition rate and with substrate temperature. However, the scaling results are not well-described by mean-field rate equation formulations which fail to account for the full complexity of the fcc(110) surface. Evidence for a transition from one to two-dimensional island growth is seen at T ~ 208 K.