The process of photoinduced electrochemical deposition of Cu structures on p-type Si substrates by local illumination with a focused laser beam is studied. The lateral dimensions of the structures formed are found to decrease with reduced laser wavelength or intensity but are independent of the duration of the illumination. Shorter minority carrier lifetimes in the semiconductor substrate lead to a further reduction of structure dimensions. The effect of spontaneous background precipitation on the Si surface is studied as a function of solution composition. The optical reflectivity can be related to the fractal surface roughness.

• Received 10 July 2003

DOI:https://doi.org/10.1103/PhysRevB.69.035334