Ag films on GaAs(110): dewetting and void growth

Scanning tunneling microscopy studies show that atomically flat but slightl y corrugated films of Ag(111) can be produced by depositing similar to 15 A ngstrom of Ag on GaAs(110) at 40 K and then annealing at 300 K. These films are six layers thick. but they also contain voids that extend to the GaAs surface. Time-dependent imaging shows void growth due to spontaneous dewett ing. Void growth is accompanied by the transfer of Ag atoms onto the terrac es where elongated, single-height Ag islands formed, with patterns reflecti ng the corrugation of the Ag film. These results demonstrate that these fil ms are thermodynamically unstable, and they reveal void growth and geometry for a multilayer film. (C) 2000 Elsevier Science B.V. All rights reserved.