Fine spots were deposited from a unstirred gold plating solution under irradiation of an argon ion laser, and the effects of laser power and electrode potential on deposition rate and fine spot size were studied. Deposition rates of 0.25μm/s were obtained at a laser power of 3W and an electrode potential of -700mV (SCE), which was 10-20 times higher than the rates of traditional gold plating. This increase was explained by convective mass transport induced by a highly localized thermal gradient and by boiling under laser irradiation. Deposition rates increased with increasing laser power and electrode potential, but the effect of laser power saturated due to boiling of the electolyte. Although the diameter of the laser beam on the substrate was about 15μm, spot diameters were several tens of micrometers due to heat conduction in the substrate and in the solution. Spot diameters increased linearly with increasing laser power and electrode potential. Defocusing of the laser beam had a remarkable effect on spot diameter.
