METAL-DEPOSITION ONTO OXIDES - AN UNUSUAL LOW INITIAL STICKING PROBABILITY FOR COPPER ON SIO2

The initial sticking probability of copper on a thin silica film has been measured in the temperature range 90-700 K using temperature programmed desorption. The copper sticking probability depends markedly on the surface temperature, varying from 0.6 +/- 0.1 at 90 K to less than 0.1 above 400 K. Upon covering the silica surface with multilayer water, the sticking probability of copper increases to approximately 1.0. These results imply that using a quartz crystal microbalance, even at 90 K, to monitor Cu deposition on silica (and likely other similar oxides) may lead to a significant error in the estimation of metal growth rate.