Surface melting of metal deposits during laser-induced chemical vapor deposition with a modulated continuous-wave laser

Abstract

Thermal laser-induced chemical vapor deposition of gold crystals on alumina substrates has been studied using a modulated Ar+ laser. Deposition of gold from dimethylgold hexafluoroacetylacetonate is accompanied by surface melting of the deposit when the laser source is modulated. Time-resolved reflectance measurements have been used to study the time evolution of the surface reflectance during growth with both modulated and unmodulated laser light. These experiments suggest that the surface melting observed with a modulated laser source is primarily due to the heat released by the exothermic decomposition of reactant adsorbed on the surface during the time that the laser intensity is off.