Waveguiding and correlated roughness effects in layered nanocomposite thin films studied by grazing-incidence small-angle x-ray scattering

Structure of Glancing Incidence Deposited TiO2 Thin Films as Revealed by Grazing Incidence Small‐Angle X‐ray Scattering

“…Figure 4 shows that the experimental GISAXS pattern of the thinnest sample can be fairly well reproduced within the distorted-wave Born approximation applied to buried scatterers, [12,13] by means of the FitGISAXS program. [12] We considered a simple model of monodisperse nanocylinders (diameter = 4.8 nm and aspect ratio = 2.7) tilted by 368 with respect to the z-axis, and randomly distributed in a TiO 2 film with 50 % porosity. Such a preliminary simulation suggests that the weak intensity present in the right half of the GISAXS pattern could be related to the second order of the form factor, which would reveal that the height distribution of the columns is quite narrow.…”

Waveguide-enhanced grazing-incidence small-angle x-ray scattering of buried nanostructures in thin films

“…These studies took advantage of the resonant XSW intensities either to enhance the scattering from buried nanoparticle layers in thin films 5,6,20 or to quantitatively separate bulk from interface scattering. [33][34][35] In addition, a significant development has been made to characterize the vertical correlations between the nanoparticles and multilayer interfaces, 7 where the vertical roughness correlations have been successfully measured in the presence of the waveguide effect so as to reveal the degree of the topographical replication of the monolayer nanoparticles across multi-interfaces.…”

“…The experimental resolution of the XSW effect is discussed in section II D. Case studies taking into the waveguide effect using the multilayer DWBA theory are discussed in section III A. In addition to the nanocomposite films with nanoparticles or nanostructures of small dimensions, 5,7 this theory can also be applied in general to either embedded or supported objects whose size effect cannot be simply treated using kinematic form factor due to significant EFI variations across the object of interest, examples for which are given in sections III B and III C.…”

Interplay between metal nanoparticles and dielectric spacing layers during the growth of Au/Si3N4 multilayers

“…As explained in Sec. Nevertheless, let us remark that such effect is expected in our case where the capping layer is relatively thin as compared to the MNPs height, 11 and that it should go stronger when t Au increases due to the strengthened perturbation of the granular layer's topology. In our case, well separated MNPs grow for t Au = 1.6 nm ͓Si 3 N 4 / Au͑1.6 nm͒ / Si 3 N 4 film͔, whereas an almost percolated 2D network is formed for t Au = 2.9 nm ͓Si 3 N 4 / Au͑2.9 nm͒ / Si 3 N 4 film͔.…”

“…The origin of this complete disordering remains unclear, but it might be due to a brutal roughness accumulation effect, 6 which has been shown to induce the gradual collapsing of the multilayer structure in ͓metal/ semiconductor͔ n films. 11 The growth mechanism of dielectric/ ͑MNPs/ dielectric͒ n multilayers is thus complex and, to our knowledge, has never been studied in a rigorous way due to incomplete structural characterization. Such interplay has been reported in more simple systems, such as monolayers of supported MNPs, whose in-plane organization strongly depends on the nature and topology of the substrate onto which they were grown.…”