Al nanocluster growth on Si(111) and Si(100) surfaces

The structure of Al films on Si in the submonolayer range has been extensively studied, but at coverages above one monolayer (ML), the structural behaviour is not elucidated as yet. The growth of nanoclusters out of Al films with 4 ML thickness, deposited on Si(111) and Si(100) surfaces by molecular beam epitaxy was studied with reflection high-energy electron diffraction, spot profile analysis low-energy electron diffraction and scanning force microscopy. Size distributions and temperature-dependent order–disorder phenomena of the clusters were measured. The Al cluster formation and structural organisation may be of relevance for practical applications such as the study of single electron tunneling and catalytic effects.