Plume investigations of the mechanisms of SiO laser ablation at 266 nm

Abstract

The ablation mechanism of SiO at the laser wavelength of 266 nm has been investigated by characterizing the composition and dynamics of neutral and charged particles produced in the ablation. The neutral and ionized composition of the plume and the dynamics of neutral SiO were investigated by time-of-flight mass spectrometry. The velocity distribution of neutral SiO molecules shows contributions of slow and fast components. The velocity distributions of charged species in the plume were investigated by a Langmuir probe technique, obtaining that the distributions shift towards higher velocities with increasing distance from the target surface. The fastest component of the velocity distribution of neutral SiO overlaps the slowest part of the velocity distribution of charged species. The average rotational energy of SiO molecules, estimated by LIF spectroscopy does not allow to draw clear conclusions about the participation of silicon oxide ion clusters as the precursors of fast SiO molecules in the plume. © 2007 IOP Publishing Ltd.