Quantification of self-sputtering and implantation during pulsed laser deposition of gold

Abstract

This work reports on the quantification of self-sputtering and implantation occurring during pulsed laser deposition of Au as a function of the laser fluence used to ablate the gold target. The experimental approach includes, on one hand, in situ electrical (Langmuir) and optical (two-dimensional imaging) probes for determining, respectively, ion and excited neutral kinetic energy distributions. On the other hand, it includes determination of the density of (i) ions reaching a substrate, and (ii) gold atoms deposited on a substrate as well as of a proportion of atoms that are self-sputtered. The experimental results supported by numerical analysis show that self-sputtering and implantation are both dominated by ions having kinetic energies ≥200 eV. They are a fraction 0.60–0.75 of the species arriving to the substrate for ablation laser fluences 2.7–9.0 J cm−2. Self-sputtering yields in the range 0.60–0.86 are determined for the same fluence range.