•Ch. Obermair, M. Müller, Ch. Klinke und Th. Schimmel
Institute of Applied Physics and Institute of Nanotechnology, Universität Karlsruhe, D-76128 Karlsruhe, Germany

The investigation of electrochemical processes on the nanometer scale is of great scientific as well as technological interest. Here, we investigate the deposition of copper from an aqueous CuSO4 solution in situ and in real time within the electrochemical cell of an atomic force microscope (AFM), and we demonstrate a new technique which allows the controlled deposition of single copper islands at predefined positions tribochemically induced with the AFM tip.

Whereas in the potential range between 20 mV and 300 mV, copper deposition was observed on the entire sample, no copper deposition was observed near the equilibrium potential. On the other hand, in the latter potential range, copper deposition could be induced locally by scanning with the AFM tip on a small scanning area while applying force loads of the order of 10 nN. In this way, small copper islands could be selectively grown, the size of the islands depending on the deposition time. Islands between 10 nm and 250 nm were grown at predefined positions. The growth of the islands was studied in situ with the AFM and the mechanism leading to the observed tribo-electrochemical activation of the deposition reaction is discussed.