Laboratory-scale quantitative actinic EUV platform for photoresist evaluation

초록

Extreme ultraviolet (EUV) lithography has become essential for advanced semiconductor manufacturing. However, the development and evaluation of high-performance EUV photoresists remain challenging due to sensitivity limitations, stochastic variations, and secondary-electron-driven reactions, which ultimately limit resolution and increase line-edge roughness. To address the need for reproducible actinic evaluation, we developed a laboratory-scale EUV photoresist sensitivity measurement (EPSM) platform based on a femtosecond high-harmonic generation (HHG) EUV source at 13.5 nm. This platform enables systematic and manufacturing-relevant screening of commercial photoresists using reproducible evaluation protocols. The EPSM system addresses the inherently low flux of tabletop EUV sources by integrating beam focusing with precise scanning control, enabling stable areal exposure and consistent evaluation. Areal exposure is achieved using a scanning EUV beam by controlling the scan distance (SD) and scan speed (SS). Using hydrogen silsesquioxane (HSQ) as a negative-tone resist, we confirmed the resulting surface roughness using atomic force microscopy (AFM). In addition, contrast curve analysis of HSQ films with varying thicknesses demonstrates the system's capability for quantitative sensitivity evaluation. This compact and flexible platform provides a reliable pathway for systematic screening of next-generation EUV photoresists. Beyond sensitivity measurements, its expandability to time-resolved and stochastic studies will further advance the understanding and optimization of photoresist performance for future high-volume manufacturing and advanced EUV lithography. © COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only.

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