LOW-POWER RESONANT LASER-ABLATION OF COPPER

We emphasize two points: (1) the properties and mechanisms of very low -fluence ablation of copper surfaces and (2) the sensitivity and selec tivity of resonant laser ablation (RLA). We present results for ablati on of bulk copper and copper thin films; spot-size effects; the effect s of surface-sample preparation and beam polarization; and an accurate measurement of material removal rates, typically less than or equal t o 10(-3) Angstrom at 35 mJ/cm(2). Velocity distributions were Maxwelli an, with peak velocities approximate to 1-2 x 10(5) cm/s. In addition, we discuss the production of diffractionlike surface features, and th e probable participation of nonthermal desorption mechanisms. RLA is s hown to be a sensitive and useful diagnostic for studies of low-fluenc e laser-material interactions. (C) 1996 Optical Society of America