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We have compared two kinds of dispersive mirrors (DMs) produced by magnetron sputtering and ion beam sputtering. One of them is a broadband DM which is known as double-angle DM, providing a group delay dispersion (GDD) of −40fs 2 in the range of 550-1050 nm. The other one is a robust highly dispersive mirror, which provides a GDD of about −275fs 2 at 800 nm and covers the wavelength range from 690 to 890 nm. For the first time, a comparison between magnetron-sputteringproduced and ion-beam-sputtering-produced dispersive mirrors is performed.Publisher's Note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Understanding the distribution of particles sputtered from a target requires an appreciation of how ions impinge on the target. In pursuit of this goal, a fully three-dimensional model of the ion trajectories in a broad ion beam, assuming full space charge compensation, Gaussian emission characteristics of the beamlets, and beamlet deflection, was constructed. The modeled ion trajectories were used to simulate target erosion, enabling a comparison between the modeled erosion and the experimental erosion. The focus was on Ar and Xe ion species at ion energies in the range of 1.4–1.9 keV and on target materials, Si, Ta, and SiO2. Conclusions were drawn on the erosion process, the potential radial inhomogeneity of the plasma in the discharge chamber of the ion source, and on the opening angle of the emission characteristics of the beamlets. For the investigated process and an applied target tilt angle of 55°, the model verified that material-specific and angle-dependent ion–solid interaction mechanisms at the atomic level played only a minor role in the target’s macroscopic surface modification in the context of the qualitative distribution of the erosion profile. In contrast, the applied sputtering geometry played a significant role.

The demand for ion beam sputtering-coated substrates is growing. In order to introduce ion beam sputter deposition (IBSD) technology into new fields of application, the deposition area must be further increased. In this context, the ion species applied for the sputtering process is an important parameter. In the present investigation, an industrial scale IBSD process was characterized with respect to productivity and layer quality by varying the ion species. Ar, Kr, or Xe broad ion beams at an ion energy of 1.8 keV were used, and the evaluation was carried out on the basis of Ta2O5 layers. The dielectric films were produced in a reactive process through the sputtering of a metallic Ta target, and their two-dimensional distributions of the coating rate R, the refractive index [Formula: see text], and the extinction coefficient [Formula: see text] were determined over a planar area of 0.9 × 1.0 m2 above the target by the collection method. R served as a measure of productivity, while [Formula: see text] and [Formula: see text] were quality parameters. Additionally, the layer composition was determined for selected samples on the collector by an electron probe microanalyzer (EPMA). As expected, the different ion-solid interaction mechanisms resulted in significant differences with regard to productivity. Linear scaling of productivity as a function of ion mass was observed. Calculations of the sputtering yield with semiempirical models or SRIM-2013, a binary collision Monte Carlo simulation program, did not confirm the observed linearity. Furthermore, the configuration with the highest productivity, Xe, led to a locally occurring and significant reduction in layer quality, more precisely, an increase of [Formula: see text]. Additionally, the layer compositions determined with EPMA confirmed that ions originating from the ion source were implanted in the thin films during their formation. A detailed evaluation of the angle-resolved energy distributions of the involved particles, simulated with SRIM-2013, was performed. However, the determination of the energies carried away from the target by backscattered ions and sputtered target atoms does not explain the observed degradation mechanism. This concludes that for the realization of future large-area coatings with IBSD, not all relevant mechanisms are yet understood in sufficient detail.