Étude des couches minces et des surfaces par réflexion rasante, spéculaire ou diffuse, de rayons X

Abstract

Nous savons que les équations de Fresnel appliquées à des dioptres supposés, parfaitement plans et homogènes, ne permettent pas de rendre compte des courbes de réflexion spéculaire fournies par des échantillons massifs ou en couche mince. Nos considérations sur divers processus de diffusion élastique ou inélastique, montrent que seule la diffusion élastique introduite par les irrégularités ou inhomogénéités de surface est importante pour l'analyse de ces courbes. Nous proposons quelques modèles de rugosité et en précisons les domaines de validité aussi bien pour la réflexion spéculaire, que pour la réflexion diffuse (suivant la loi des réseaux). Ces modèles sont comparés avec les courbes expérimentales obtenues sur des échantillons massifs de titane, de silicium et de germanium, avec les rayonnements Kα 1 du cuivre ou du chrome

Probing surface and interface morphology with Grazing Incidence Small Angle X-Ray Scattering

“…The origin of reciprocal space is located (i) along 2θ f , in the middle of the two lobes when the image is known to be symmetric, and (ii) along α f , by setting the Yoneda's peak at the substrate α c value at the early beginning of the growth, as given by the transmission function T (α f ) inside the substrate. The only discrepancy that was found between the theoretical T (α f ) function [100] (a) and the [110] (b) direction of the MgO(001) substrate. The intensity is represented on a logarithmic scale.…”

“…21a with b. Indeed, the intensity along the q y direction, at the Yoneda peak position, is clearly larger when the X-ray beam is along [100] as compared to along [110]. This indicates that there is a scattering rod along the [010] direction.…”

Optical and Structural Properties of Ultra‐thin Gold Films

“…X-ray reflectivity (XRR) measurements were made with a parallel beam on a PANalytical [25,26] Further details of the procedures employed in the fitting software can be found on the manufacturer's website.…”

Grazing Incidence X‐Ray Methods for Near‐Surface Structural Studies

“…This, however, could only be applied to perfectly fl at surfaces or multilayers. Following the later investigations of Cowley and Ryan [14] and of N é vot and Croce [15,16] , roughness could also be taken into account in the analysis. The approach of Cowley and Ryan was to apply a roughness -related Debye -Waller type factor to the Fresnel refl ection coeffi cient from each interface.…”

“…In 1959, X -ray refl ectometry was used to determine the density of copper fi lms [21] , and in 1960 the annealing and oxidation of evaporated fi lms of Cu, Ni, Ge, and Se was studied [22] . However, the technique remained relatively obscure until further investigations were conducted during the 1970s [15,16] , whereby surface and interfacial roughness could be taken into account in the analysis procedures. It was at this point that the potential of GXRR became apparent and the technique began to attract the attention of various research groups.…”