Small angle X-ray scattering (SAXS) was used to characterize the line cross section of nanoline gratings fabricated using electron beam lithography (EBL) patterning followed by anisotropic wet etching into silicon single crystal. SAXS results at normal incidence clearly bear the signature of non-uniformity of line width within the gratings; this non-uniformity is subsequently confirmed with scanning electron microscope results. The proximity effect of EBL is believed to be the culprit of the observed line width variation. To fit the SAXS results quantitatively the line width near the periphery of the pattern has to be 80% greater than that of the central region whereas the cross section of nanolines can be modeled as a simple rectangular shape as expected from the anisotropic wet etching kinetics.
Citation: Thin Solid Films
Pub Type: Journals
small angle X-ray scattering, electron beam lithography, anisotropic wet etching, line width, silicon wafer, line gratings