Center for Functional Nanomaterials Seminar

The development of novel resists and processes that can match the challenges posed by the next generation of lithography partly hinges on our ability to develop new methods for extracting spatial information with sub-nm precision at each step of the lithographic process. This is particularly important for EUV resists, which tend to suffer from the seemingly inescapable trade-off between improving photon sensitivity and resolution, while reducing line edge roughness (LER). The strategies used to optimize this trade-off rely on tailoring the physicochemical mechanisms that take place before the final development of the resists, thus finding a way to characterize the structure of their latent image is critical to future progress. To meet some of these challenges, resonant x-ray scattering (ReXS) has emerged as a powerful technique which leverages the chemical contrast that exists between exposed and unexposed regions before the final development step in order to produce the average cross-sectional profile of the latent image with sub-nm precision. Most recently, the ReXS technique was demonstrated in a grazing incidence configuration by using exposure-induced differences in carbon chemistry in order to extract the latent image from a chemically amplified resist directly on a silicon substrate. In this presentation, we leverage chemical contrast from other active elements in a given resist and expand on the potential benefits, drawbacks (i.e. beam damage and experimental configurations), and challenges involved in performing such measurements even before the post-exposure baking step has taken place. As an additional demonstration of the utility of ReXS techniques for operando interface characterization, I will present results from a newly-developed in-situ cell for gas/liquid flow and electrical biasing that is compatible with many "soft" and "tender" X-ray beamlines has been used to study a Ni/Ni(OH)2 core/sh