INFLUENCE OF THE DEPOSITION RATE ON THE STRUCTURE OF THIN METAL LAYERS

The influence of the deposition rate on the morphology of epitaxial Sb layers on GaAs(110) is investigated. Layers with a nominal thickness of 30 monolayers (ML) were deposited with varying deposition rates (10 to 0.03 ML/min) on substrates kept at room temperature. Characterizat ion techniques employed are Raman scattering, low energy electron diff raction (LEED), X-ray reflectivity and scanning probe microscopy. A wi de variation of layer morphology is obtained dependent on the depositi on rate: lowering the deposition rate generally results in larger isla nd size and rougher surfaces. In most cases, the Sb layer is of rhombo hedral structure. However, in a very narrow range of deposition rates, we found a growth mode of Sb, which is similar to a pseudo-cubic phas e. This phase was found so far only for a thickness below 15 ML after annealing at 475 K. (C) 1998 Elsevier Science S,A.