Harnessing the extreme ultraviolet for critical dimension metrology

Published

March 17, 2026

Author(s)

Bryan Barnes, Purnima P. Balakrishnan, John Burnett, Aaron Chew, Colton Dudley, Thomas Germer, Steven Grantham, Stephanie Moffitt, Eric Shirley, Martin Sohn, Daniel Sunday

Abstract

The semiconductor industry has long adopted visible and ultraviolet wavelengths for optical critical dimension (OCD) measurements. Decreasing feature sizes, increasing architecture complexity, and troublesome parametric correlations all motivate approaches leveraging shorter wavelengths into the vacuum- and extreme-ultraviolet (VUV, EUV) spectral regions. Straightforward extensibility of established OCD techniques in the visible range into these vacuum wavelengths is greatly hampered by absorption. We review the initial and developing efforts to utilize these vacuum wavelengths for model-based measurements of CD, often labeled "EUV scatterometry" in the literature. The predominant mode for EUV-based CD metrology is diffraction, while our group at the National Institute of Standards and Technology (NIST) is pursuing both EUV diffractometry and spectroscopic ellipsometry at VUV and EUV wavelengths. Current progress will be presented in context of a gaps analysis of EUV scatterometry for near-line and in-line process control.

Proceedings Title

Frontiers of Characterization and Metrology for Nanomaterials 2026

Conference Dates

March 16-19, 2026

Conference Location

Monterey, CA, US

Pub Type

Conferences

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Keywords

Extreme ultraviolet, scatterometry, diffractometry, spectroscopic ellipsometry, vacuum ultraviolet

Citation

Barnes, B. , Balakrishnan, P. , Burnett, J. , Chew, A. , Dudley, C. , Germer, T. , Grantham, S. , Moffitt, S. , Shirley, E. , Sohn, M. and Sunday, D. (2026), Harnessing the extreme ultraviolet for critical dimension metrology, Frontiers of Characterization and Metrology for Nanomaterials 2026, Monterey, CA, US, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=961343 (Accessed September 1, 2026)

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