Nucleation and growth of Cu adsorbates on hydrogen-terminated Si(111) surface in solution

We report, for the first time, the behavior of Cu nucleation and growth on hydrogen- (H-) terminated Si(111) surface in solution. The samples were prepared by immersing H-terminated Si(111) surfaces in Cu-containing sulfuric acid solution with various immersion times. The Cu-adsorbed silicon surfaces were observed with an atomic force microscope (AFM). Statistical analysis of the AFM images indicates that Cu nucleation occurred immediately after immersing into the solution, and the coverage of the surfaces with Cu adsorbates increased linearly with immersion time although the average height increased negligibly. These results suggest that the growth behavior of Cu adsorbate on H-terminatcd Si(111) surfaces is fundamentally two-dimensional due to the long-range migration of Cu ions which were reduced at the silicon/solution interface.