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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 resputtering effects are quantified by monitoring the deposition rate during growth of elementary and multilayer films. It is shown that preferential resputtering and, therefore, composition deviations of alloy films can be reduced at laser fluences close to the ablation threshold or even better under Ar gas pressure of about 0.05 mbar. The experimental results are described by a model, which includes atom deposition on the film surface, implantation of energetic ions below the surface and resputtering of atoms from the top monolayer.

To determine the effective sputter yield during pulsed-laser deposition a method by measuring the deposition rate on tilted substrates is proposed. Under vacuum conditions, sputter yields of up to 0.17 and 0.55 were found at a laser fluence of 4.5 J/cm2 for Fe and Ag, respectively. These strong resputtering effects are induced by the large fraction of energetic ions occurring during deposition. With decreasing laser fluence or increasing Ar gas pressure, the sputter yields are reduced due to a decrease of the kinetic energy of the ions. For the deposition of stoichiometric films, an optimum Ar partial pressure of about 0.04 mbar exists, where the deposition rate is highest and the sputter yield is reduced.

In situ stress measurements were performed on polycrystalline Permalloy and Ag thin films laser deposited in ultrahigh vacuum (UHV) and at different Ar gas pressures. In UHV, when the kinetic energy of the particles is high (about 100 eV), in the initial growth stage the stress is dominated by the surface energy and intermixing effects. With increasing deposition time, capillary-induced compressive growth stress is observed. Additionally, the film stress is strongly influenced by the growth mode (island growth or layer-by-layer growth). In the case of Volmer–Weber growth, island zipping generates tensile stress, as soon as island impingement and coalescence occurs. In the late stages, compressive stress due to shot-peening and implantation dominates the measurements, similar as in sputtered films. The depth of influence of the impinging particles is determined to be about 3 nm. With increasing Ar pressure (or at low laser fluence) the impinging particles are slowed down and implantation or intermixing effects are diminished. This is accompanied by changes in the film morphology and texture. At high Ar pressures a compressive-to-tensile transition occurs and the laser deposited films become more comparable to evaporated samples with an open structure. These results can be understood by a combination of stress formation and relaxation effects below the film surface.

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