Abstract
Metal deposition (plating) and etching rates are remarkably enhanced by laser illumination with and without an external potential. Plating of Ni, Cu or Au on semiconductors by laser illumination is expected to be a useful method for maskless patterning in microelectronics industry. Selective etching of specific elements in alloy substrates (e.g. stainless steel) by laser with nitric acid solution yields the surface enrichment of another elements (such as Cr) in the matrix followed by passivation, leading to the improvement of corrosion resistance. The mechanism for the laser enhancement of electrochemical reactions is based primarily on a photothermal process, which causes (1) an increase in the charge transfer rate, (2) a shift in the rest potential to more positive values with increasing temperature, and (3) an increase in the mass transport limited current due to the local microstirring of a fluid.
