Nano-structuring of sputtered gold layers on glass by annealing

The crystalline structure and surface morphology of gold nano-structures prepared by sputtering on a glass substrate are studied. The properties of the gold nano-structures were determined at room temperature and after annealing at 300 °C. XRD analysis provided information about the gold crystalline structure. Significant difference in the dependence of the lattice parameter on the sputtering time was found between the as-sputtered and annealed samples. By the XRD method the texture, crystallite size and lattice stress were also determined. With increasing sputtering time the layer thickness and the size of crystallites increased. Another rapid enlargement of the crystallites is observed after annealing. On the as-sputtered samples the value of micro-deformation depends on the structure thickness. After annealing, however, the micro-deformation is nearly constant regardless of the sputtering time. On both, the as-sputtered and the annealed samples the gold crystallites are preferentially [111] oriented. After the annealing significant changes in the structure surface morphology and a dramatic increase of the surface roughness are observed due to a structure relaxation at increased temperature.