1 June 2018 Speckle metrology for extreme ultra-violet lithography
Author Affiliations +
Stochastic effects in extreme ultraviolet lithography are contributed by the EUV optical speckle and diffusion chemistry of the photoresist. These cause line edge roughness (LER) in the etched features, shrinking the process window at the sub-20nm lithography node. We explore possibilities of utilizing the speckle for optical metrology and resist characterization by measuring the latent image of the EUV light on photoresist. The latent image on a standard photoresist measured using atomic force microscopy is shown to linearly depend on the aerial image intensity within a specific dose range, hence serving as an in-situ imaging modality to measure the EUV aerial image without a camera. Potential applications include EUV wavefront measurement, resist characterization, and LER engineering.
Conference Presentation
© (2018) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
A. Shanker, A. Shanker, L. Waller, L. Waller, G. Gunjala, G. Gunjala, A. Wojdyla, A. Wojdyla, D. Voronov, D. Voronov, P. Naulleau, P. Naulleau, "Speckle metrology for extreme ultra-violet lithography", Proc. SPIE 10583, Extreme Ultraviolet (EUV) Lithography IX, 105830T (1 June 2018); doi: 10.1117/12.2299605; https://doi.org/10.1117/12.2299605

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