Mitigating X‑ray–Induced Damage in CD‑SAXS Metrology of EUV Resists

Accurate characterization of nanoscale features in Chemically Amplified Resists (CARs) is essential for advancing Extreme Ultraviolet (EUV) lithography. Critical‑Dimension Small‑Angle X‑ray Scattering (CD‑SAXS) collects X‑ray scattering patterns as a function of sample angle; the dataset is fit to a model to quantify the three‑dimensional geometry of nanoscale features. While this technique is a robust metrology for inorganic patterns, measurements of organic and chemically active materials can be plagued by beam‑induced damage during X‑ray exposure. In this work, we measure beam damage across multiple resist systems and present approaches to mitigate it without compromising signal‑to‑noise ratio (SNR). The scattering data are modeled with a rounded‑trapezoid geometry to extract parameters such as linewidth, height, and sidewall angle. We compare CD‑SAXS results with Critical‑Dimension Scanning Electron Microscopy (CD‑SEM) and Transmission Electron Microscopy (TEM), confirming utility while exposing tradeoffs.