Probing Buried Chemical Profiles in Novel EUV Resists with Energy-Tunable X-Rays

With the adoption of extreme ultraviolet (EUV) lithography across the semiconductor industry, there comes a need to develop new resist materials that will become the mainstay enabling technology. This development places pressure on the metrology community to develop adequate non-destructive techniques capable of measuring the sub-10 nm patterns that such resists are meant to produce. Recent progress in grazing incidence and resonant x-ray scattering techniques have shown particular promise at being able to address part of these characterization challenges.^1,2
In this work, we show how resonant scattering contrast can harness spatially distributed chemical heterogeneities within exposed resist in order to probe their buried profile. Specifically, by focusing on a novel photoresists containing both organic and inorganic components, we demonstrate the insights into critical parameters gained by performing resonant scattering measurements at various energies and configurations.

1. G. Freychet, I. A. Cordova, T. McAfee, D. Kumar, R. J. Pandolfi, C. Anderson, S. D. Dhuey, P. Naulleau, C. Wang and A. Hexemer, J Micro-Nanolith Mem 18 (2) (2019).
2. G. Freychet, D. Kumar, R. J. Pandolfi, P. Naulleau, I. Cordova, P. Ercius, C. Y. Song, J. Strzalka and A. Hexemet, Phys Rev Appl 12 (4) (2019).