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

Scanning tunneling microscopy studies show that atomically flat but slightly corrugated films of Ag(111) can be produced by depositing ∼15 Å 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 dewetting. Void growth is accompanied by the transfer of Ag atoms onto the terraces where elongated, single-height Ag islands formed, with patterns reflecting the corrugation of the Ag film. These results demonstrate that these films are thermodynamically unstable, and they reveal void growth and geometry for a multilayer film.