Novel Growth of Ag Islands on Si(111): Plateaus with a Singular Height

Growth and transport properties of thin Ag films on Si(111) are investigated by scanning tunneling microscopy and in situ resistivity measurements. At low coverage, the Ag adatoms form isolated islands with a strongly preferred height and flat tops, rather than commonly observed pyramids. Such plateaus increase their lateral extent with coverage without changing height, forming a percolated network with sharply reduced resistivity above a critical coverage. This behavior suggests how the quantized electrons confined in the Ag islands could influence the growth, and may provide a unique pathway to prepare nanometer-scale structures with intriguing mesoscopic properties.