Nucleation and growth of copper on mesoporous silicon by immersion plating

Copper deposition was investigated on electrochemically etched mesoporous silicon epilayers of pore diameter 7 nm, porosity 45% and surface area 500 m(2) cm(-3) by immersion plating in an aqueous solution containing Cu2+ ions. When the layers were immersed in a 0.1 M CuSO4 center dot 5H(2)O aqueous solution for different time-periods ranging from 1 to 60 min, elemental copper was deposited on the surface. Fourier transform infrared (FTIR) spectroscopy in transmittance mode was carried out on copper deposited porous silicon (PS) samples to infer the changes in the surface bonding of the PS. It was clearly observed from x-ray diffraction patterns and FTIR spectra that the reduction of copper ion on PS was accompanied by gradual and finally complete oxidation of the PS epilayers surface. Scanning electron microscopy has been used to study the morphology of the copper aggregates at the PS epilayers surface.