Ex situ scanning tunneling microscopy study of Cu nanowires formed by electroless deposition at atomic‐step edges of flat Si(111) surfaces

Abstract

AbstractWe immerse flattened H‐terminated Si(111) surfaces into Cu‐containing ultralow‐dissolved‐oxygen water. We confirm, by atomic force microscopy (AFM) observations, that Cu wires with the width of about 10 nm are formed at atomic‐step edges of the Si(111) surfaces. On the contrary, ex situ scanning tunneling microscopy (STM) images show grooves at step edges on this surface. Both XPS spectra of Cu signals and possible chemical reactions during the electroless deposition of Cu atoms at the step edges suggest that Si oxides underneath the Cu nanowires are the origin of the grooves in the STM images. Furthermore, we present the possibility of controlling the width of one‐dimensional Si oxides along the Cu nanowires at step edges by subsequent processes using oxidants. Copyright © 2008 John Wiley & Sons, Ltd.