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.