Detachable (111) Cu films formed in ultrahigh vacuum

Epitaxial Cu films 1200 Å thick were formed on evaporated (111) NaCl films in an ultrahigh vacuum RHEED camera. Information on the surface structure, microstructure, and surface smoothness was obtained by in situ RHEED techniques. The microstructure of the Cu films was also studied by transmission electron microscopy. (111) Cu films were doubly positioned. The smoothness of the films increased with increasing Cu deposition rate. The microstructure of the as-deposited Cu films also depended upon the deposition rate. Annealing the Cu films improved their perfection. However, the final microstructure of the annealed films was independent of the initial deposition rate. These annealed Cu layers were used as substrates for the epitaxial growth of Ag films several monolayers thick.