Structural and electrical properties of thin d.c. magnetron-sputtered gold films deposited on float glass

The combination of in situ electrical resistivity measurements and ex situ tapping-mode atomic force microscopy (AFM) in air was used to study the surface topography and the electrical properties of thin d.c. magnetron-sputtered gold films on float glass substrates. In particular, the influence of the deposition temperature and a subsequent isochronous annealing process on the electrical resistivity and the surface structure of the polycrystalline gold films were analysed. The results show that a minimum surface roughness of about 0.4 nm was achieved for a deposition temperature of about 350 K. After the annealing process, an increase of the surface roughness and the lateral crystallite size was observed in general, suggesting that the measured decrease in resistivity during annealing is not related to a smoothing of the surface, but to the decrease of the grain-boundary scattering of the conduction electrons. Assuming that the annealing processes are diffusion-limited reactions, we calculated the corresponding activation energies from the irreversible branch of the annealing curves, yielding values of about 0.6–1.0 eV, which also correspond to grain-boundary diffusion. Copyright © 2006 John Wiley & Sons, Ltd.