Growth and characteristics of Ge on Ru(0001)

Abstract

Scanning tunneling microscopy (STM) and x-ray photoemission spectroscopy (XPS) studies of germanium growth on Ru(0001) were carried out. STM measurements showed a typical Stranski-Krastanov growth mode of Ge on Ru(0001), i.e. first atomic wetting layer is formed in the submololayer range, and the formation of islands on top of a flat first layer occurs for subsequent layers. XPS measurements showed a weak interaction between Ge and the substrate of Ru(0001). The Ru 3d5/2 and Ru 3d3/2 corelevels of Ru(0001) are located at 279.8 and 284.0 eV in binding energy respectively. Upon Ge growth, up to a thickness of about 20 atomic layers, the Ru 3d corelevels shift downward in binding energy by an amount of about 0.2 eV, while the Ge 3d corelevel shift upward in binding energy from the Ge low coverage limit of 28.9 eV to 29.0 eV, with a relative change of 0.1 eV.