CLUSTER ION-BOMBARDMENT ON ATOMICALLY FLAT AU(111) SOLID-SURFACES

Energetic cluster ion bombardment shows unique and complicated interac tions between constituents of the cluster and atoms of the target surf ace. Scanning tunneling microscopy (STM) observation is one of the mos t powerful methods to investigate the cluster ion-solid surface intera ction. We have observed crater-shape traces on highly oriented pyrolit ic graphite (HOPG) surface bombarded by energetic Ar cluster ions. How ever, STM images of HOPG surfaces are influenced by special electronic surface states. In this paper, Ar monomer and cluster ions are bombar ded on Au( iii) surfaces on mica to observe ion traces by STM. In addi tion, the relationship between the parameters of cluster ion beams and the features of ion traces are discussed. The STM observation showed that Ar cluster ion bombardment had circular crater-like shapes, and t heir diameters were proportional to the cubic root of ion energy. Thes e indicate that the kinetic energy of cluster ions is deposited on the surface isotropically. (C) 1998 Elsevier Science S.A. All rights rese rved.