Atomistic investigation on the initial stage of growth and interface formation of Fe on H-terminated Si(111)-(1 × 1) surface

The initial growth process of a Fe thin film on a hydrogen-terminated Si(111)-(1 × 1) surface is investigated through direct atomic scale measurements by using scanning tunneling microscopy (STM) and spectroscopy (STS). By depositing Fe onto the substrate at room temperature, nanometer-size Fe clusters having a (111)-oriented body-centered-cubic structure are formed on the substrate surface with maintaining the (1 × 1) structure. As the clusters grow, hill-like structures composed of {110} nano-facets appear on the surface of the Fe clusters. In the empty-state STM image, a depression of the substrate surface is observed at the periphery of a Fe nanocluster. The depression indicates the formation of a Schottky junction between the Fe nanocluster and the substrate surface.