Initial stage deposition of Ag on the Si (100)2x1 surface studied by scanning tunneling microscopy

Abstract

The initial stage deposition of Ag on the Si(100)2x 1 surface at room temperature has been studied by scanning tunneling microscopy/spectroscopy. A thermal evaporation source made of a high-purity Ag coiled around a 10 mil tungsten wire was used. The three types of Ag clusters were observed: (1) Single Ag atom adsorbs on the hollow site between two dimers in the adjacent dimer rows, which is in agreement with the result derived by Hanbucken and Neddermeyer, Surf. Sci. 114, 563 (1982). (2) The Ag atoms form linear chains perpendicular to the dimer rows. (3) Two-dimensional islands of Ag atoms are formed. The absorption site is same as the single Ag adsorption; the local p (2 X 2) structure was observed for the two-dimensional islands. The STS on one-dimensional and two-dimensional islands showed nonmetallic /- V characteristics, which is consistent with the long distance (7.7 A) between each Ag atom. The stability of two-dimensional islands will be discussed. © 1990, American Vacuum Society. All rights reserved.