8 November 2012 EUVL mask inspection at Hydrogen Lyman Alpha
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Mask inspection is an outstanding challenge for Extreme Ultra-Violet Lithography (EUVL). The purpose of this investigation is to compare imaging characteristics of ArF and KrF inspection sources to imaging characteristics using a source at the Lyman-alpha line of Hydrogen at 121.6nm (HLA). HLA provides a raw resolution improvement of 37% to ArF and 51% to KrF, based on proportional wavelength scaling. The HLA wavelength is in an atmospheric transmission window, so a vacuum environment is not required. Our comparison uses rigorous vector imaging techniques to simulate partially coherent illumination schemes and reasonably accurate mask material properties and dimensions. Contrast is evaluated for representative spatial frequencies. Imaging and detection of defects are also considered with NILS and MEEF. The goal is high throughput inspection with maximum resolution, contrast, and sensitivity.
© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Thiago S. Jota, Thiago S. Jota, Tom D. Milster, Tom D. Milster, } "EUVL mask inspection at Hydrogen Lyman Alpha", Proc. SPIE 8522, Photomask Technology 2012, 85221V (8 November 2012); doi: 10.1117/12.977205; https://doi.org/10.1117/12.977205


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