Nanocluster Epitaxy by Annealing: Ag on H-terminated Si (111) Surfaces

We report an experimental investigation on the morphology and orientation of Ag nanoclusters by RT deposition and subsequent annealing. We show that epitaxial Ag clusters of 2 ∼ 6 nm in diameter can be synthesized in this way. The RT self-assembled Ag clusters grow as mostly single-crystal crystallites with Ag(111)//Si(111), but the in-plane orientation has a dispersion of ∼ 9° centering at Si[110] direction. Upon annealing, the Ag clusters drastically rotated to the epitaxial configuration with the in-plane orientation aligned to the Ag[110]//Si[110] direction. The rotation and epitaxy of the Ag nanoclusters are explained based on a coincident site lattice model and interface energy minimization.