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PUBLICATIONS

Ellipsometry in the EUV Regime

Published

Author(s)

Aaron Chew, Bryan Barnes, Eric Shirley, Thomas Germer

Abstract

We propose and analyze the sensitivity of an ellipsometer that uses extreme ultraviolet (EUV) light from the synchrotron SURF-III. The ellipsometer employs a four-mirror geometry to control polarization, as documented in the associated patent. With a combination of Monte Carlo simulations and least squares fitting, we examine the benefits of both employing shorter wavelengths and polarization control as a measurement tool for several industrially relevant geometries, and observe the parametric decorrelation of important fitting parameters. This decorrelation is explained with simplified models. We find that the shorter wavelength of EUV light yields clear benefits for scatterometry experiments, and polarization control offers a new degree of freedom control that can be extremely beneficial when other degrees of freedom, such as wavelength control or angle of incidence, are inaccessible or unable to decorrelate parameters.
Proceedings Title
Metrology, Inspection, Process Control, xxxix
Volume
13426
Conference Dates
February 23-27, 2025
Conference Location
San Jose, CA, US
Conference Title
SPIE Advanced Lithography and Patterning
Pub Type
Conferences

Download Paper

https://doi.org/10.1117/12.3053165
Local Download

Keywords

diffractometry, ellipsometry, EUV, maximum likelihood estimation, Monte Carlo, nanofork, nanosheet, RCWA, sensitivity, ultraviolet
Physics and Optical physics and communications

Citation

Chew, A. , Barnes, B. , Shirley, E. and Germer, T. (2025), Ellipsometry in the EUV Regime, Metrology, Inspection, Process Control, xxxix, San Jose, CA, US, [online], https://doi.org/10.1117/12.3053165, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=959589 (Accessed October 20, 2025)

Issues

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Created April 24, 2025, Updated September 24, 2025
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