Metallic etching by high power Nd:yttrium–aluminum–garnet pulsed laser irradiation

A Nd:yttrium–aluminum–garnet pulsed laser, with 1064 nm wavelength, 9 ns pulse width, and 0.9 J maximum pulse energy, is employed to irradiate in vacuum different metal targets (Al, Ti, Ni, Cu, Ta, W, Au, and Pb). In order to measure the erosion thresholds, the etching rates, and the chemical yields, a mass quadrupole spectrometer is interfaced to the vacuum chamber. Etching process shows a threshold, which ranges between 0.1 and 1.6 J/cm 2 for lead and tungsten, respectively. Etching rates range between 0.3 and 10 μg/pulse for copper and lead, respectively. The irradiation produces chemical yields ranging between 0.04 and 0.6 atoms/100 eV for copper and lead, respectively. A simple theoretical approach is presented to justify obtained results. The objective of collected data concerns the possibility to use ejected atoms, neutral and ionized, in an electron cyclotron resonance ion source, in order to provide high current, multiply charge ion beams.