Fourier Scatterometry for Characterization of Sub-wavelength Periodic Two Photon Polymerization Structures

摘要

In the present paper we extend Fourier-Scatterometry by the use of the coherent properties of white light for the characterization of sub-wavelength periodic gratings of photosensitive material structured by two-photon polymerization. Our goal is a fast and precise optical characterization of periodical gratings of sub 100 nm size. The investigated structures include gratings produced by two-photon polymerization of photosensitive material and typical semiconductor test gratings. A Fourier-Scatterometer has been set up using a white light source and also additionally a reference-branch for white-light-interference (WLI). A sensitivity comparison between Fourier-Scatterometry and WLI-Scatterometry is presented.