Quantification of resputtering during pulsed laser deposition

During pulsed laser deposition in ultrahigh vacuum, the deposited material consists of a large fraction of ions with kinetic energies in the range of 100 eV. In many cases, these energetic particles induce resputtering at the film surface and lead to composition deviations. For Fe-Ag the resputterin g effects are quantified by monitoring the deposition rate during growth of elementary and multilayer films. It is shown that preferential resputterin g and, therefore, composition deviations of alloy films can be reduced at l aser fluences close to the ablation threshold or even better under Ar gas p ressure of about 0.05 mbar. The experimental results are described by a mod el, which includes atom deposition on the film surface, implantation of ene rgetic ions below the surface and resputtering of atoms from the top monola yer. (C) 2001 American Institute of Physics.