Grazing-incidence X-ray reflectometry and fluorescence analysis of the metallic-coated sinusoidal diffraction grating

Grazing incidence X-ray reflectometry (GIXRR) and fluorescence (GIXRF) analysis of the metallic-coated diffraction grating has been conducted. The grating has the sinusoidal-type groove profile derived from the atomic-force microscopy measurements. Using the developed methods of GIXRR and GIXRF, we theoretically and experimentally investigate angular dependences of the specular reflected and emitted radiation intensity of the Al-coated 400 mm grating with a Cr adhesion layer of the thickness of ~2 nm on the SiO2 substrate working in extreme conical and classical diffraction mounts for the incident wavelength of ~0.1541 nm and the grazing-incidence angle range of ~0.05–0.5 deg. The specular reflectance (the 0-th order efficiency) as well as the specular fluorescence intensity have been found from solutions of the respective vector Helmholtz equations. In order to determine the fluorescence intensity, we have used the approach based on a method of fundamental parameters using the reciprocity theorem.