Surface structures of Au-Si compounds grown on flat and stepped Si substrates

The experimental evidence for the formation of surface Au-Si structures is reported. The structures have been obtained in the process of surface segregation in Au thin films grown on Si substrates at annealing temperatures well below the Au-Si eutectic temperature. The surface exhibits plethora of various local phases, as revealed by scanning tunneling microscopy. These structures are discussed in relation to theoretically predicted structural models of Au-Si. The role of substrate anisotropy is also investigated. Our findings shed light on the alterations in the surface morphology of Au-Si complexes, which have significant implications for the development of novel materials and interfaces.