In the present work copper nanostructures were deposited on p-type silicon (p-Si) by means of a selective electrochemical reaction. p-Si was implanted with Ga+ ions at an energy of 30 keV with different ion fluences (1 x 10(12) to 1 x 10(16) ions/cm(2)); in a second step Cu was deposited selectively at the implantation sites at different cathodic potentials and for different exposure times. Deposition time as well as potential strongly affect the morphology of the Cu deposit. Extended polarization leads to overgrowth of the initial defect patterns resulting in a loss of lateral growth control. By adjusting the implant and electrochemical conditions we were able to obtain deposits as fine as 300 nm (width), which is also the lateral resolution of the focused ion beam process used, i.e., corresponds to the ion beam distribution.