X-ray diffraction by phase diffraction gratings

The diffraction properties of phase gratings with the period D = 1.6, 1.0 and 0.5 µm fabricated on an Si(111) crystal by e-beam lithography were studied by triple-axis X-ray diffraction. A 100 nm-thick tungsten layer was used as a phase-shift layer. It is shown that the presence of a grating as a phase-shift W layer on the surface of the Si(111) crystal causes the formation of a complicated two-dimensional diffraction pattern related to the diffraction of X-rays on the phase grating at the X-ray entrance and exit from the crystal. A model of X-ray diffraction on the W phase diffraction grating is proposed.