ABSTRACTWe present data on micrometer-scale localized single-pulse laser irradiation of Au, Cu, Al, or Ti films on borosilicate glass substrates. These metals represent a range of thermal properties, chemical reactivity levels, and relevance to specific applications. A mask projection technique employing a Q-switched Nd:YAG laser, emitting at its fourth harmonic of 266nm, was used to produce the irradiation spots in this work. The metal films, deposited by RF-sputtering, had thicknesses of several hundred nanometers. Sample irradiation was performed in either vacuum or ambient air, and the resulting microstructures were examined by electron microscopy. The results indicate that irradiation of Cu films can lead to the formation of bumps, sharp cones or protrusions. However, the controllability of these structures on Cu films is limited, compared to those formed on Au or Si. The results, upon irradiation of Ti films, are limited to melting and surface roughening or ablation openings, regardless of the conditions of irradiation, film thickness, substrate or ambient gas. The modifications that occur within Al films are reproducible, but limited in shape and size.
Analyses of Self-Focusing Phenomenon and Temperature Rise in Fused Silica by Ultrashort Pulse Laser Irradiation
