EPITAXIAL-GROWTH OF THIN COPPER LAYERS ON CU(111) STUDIED BY HIGH-RESOLUTION LOW-ENERGY-ELECTRON-DIFFRACTION

The morphology of ultrathin epitaxial copper films (2.5 ML) on a Cu(111) substrate is investigated by high-resolution low-energy-electron-diffraction (HR-LEED). Analyzing the spot profile of the diffracted electron beam (SPA-LEED) provides detailed information about defects of the growing film, especially steps. Thus, from the broadening of the spot the density of steps and their angular distribution are evaluated for various deposition conditions. At low temperature the film grows with nearly no diffusion of the adatoms across step edges. At high temperatures the film starts to build facets whose angles with the substrate depend on the temperature during and after deposition of the film. The annealing behaviour of a film grown at low temperature is also studied with respect to step density and asperity height. Thus the morphology of copper films under various deposition and annealing conditions can be investigated quantitatively in full detail by careful measurements and evaluation of the spot profiles. © 1990.