Characterization of Cross-sectional Profile of Periodic Surface Nanostructure Using CD-SAXS

Critical dimension small-angle x-ray scattering (CD-SAXS) with a grazing incidence geometry, which was developed by authors, has been successfully applied to the cross-sectional profile measurements of line-and-space (L/S) patterns and hole patterns on quartz substrates. I have calculated reciprocal space mapping (RSM) data from the nanostructures based on a distorted wave Born approximation method to take the refraction and the reflection at the interfaces between layers into account, and the cross-sectional profiles have been analyzed by a model-based least-square method. The obtained cross-sectional profiles were compared with SEM for top-view and TEM for side-view. As results of the comparisons, it was shown that the cross-sectional profiles obtained by the CD-SAXS well reproduced the electron microscope results. These results demonstrate the applicability of the CD-SAXS to the nanoscale structural metrology.