On the intersection of grating truncation rods with the Ewald sphere studied by grazing‐incidence small‐angle X‐ray scattering

In this work a grating made of lines having a height of 55 nm and a period of 450 nm has been characterized by grazing-incidence small-angle X-ray scattering (GISAXS). The GISAXS patterns are characterized by a series of spots corresponding to the intersection of the Ewald sphere with the grating truncation rods (GTRs). When the grating lines are almost parallel to the direct beam, the location of these spots is very sensitive to any change in the azimuthal angle. The precise location of the intersection of the GTRs with the Ewald sphere can be calculated for any azimuthal angle. From this analysis we can estimate the statistical coverage of the grating, its period and the width of the lines. In addition, the anisotropy of the width of the spots in the qz direction is interpreted in terms of wavelength spread and angular divergence of the incident beam.