NIST efforts in extreme-ultraviolet metrology

Published

November 21, 2023

Author(s)

Charles S. Tarrio, Steven Grantham, Rob Vest, Thomas A. Germer, Bryan Barnes, Stephanie Moffitt, Brian Simonds, Matthew Spidell

Abstract

For several decades, the National Institute of Standards and Technology (NIST) has actively supported metrology programs for extreme ultraviolet (EUV) lithography. We will describe our existing programs in optics lifetime, reflectometry, and radiometry. Recent developments include developing quantitative models for both carbonization and oxidation of optics under UV illumination and use of a cryogenic radiometer to calibrate transfer-standard detectors from 4 nm to 400 nm. We describe two programs currently in planning. The first of these is development of a method to calibrate high-power pulsed radiation detectors using a calorimeter. Our current primary standard detectors for 13 nm are based on synchrotron radiation with incident powers of a few microwatts or less. EUV production tools need to measure pulse trains with many hundreds of watts of average power. We will begin this work on our existing low-power detector-calibration facility and use higher-power beamlines with overlapping power ranges and the linearity of synchrotron radiance with stored beam current to extend the calibrations to higher powers. Second, we present a Mueller matrix ellipsometry and scatterometry system covering the far-to-extreme ultraviolet spectral range. This system is expected to achieve the requisite variable polarization and diattenuation control with an entirely reflective optical system. By extending scatterometry to short wavelengths, we intend to demonstrate improved sensitivity and accuracy of parameter retrieval from microfabricated devices. These programs complement NIST's existing far- and extreme-ultraviolet radiometry and metrology programs and expand our support for critical semiconductor manufacturing.

Citation

Proceedings of the SPIE

Pub Type

Others

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https://doi.org/10.1117/12.2686832

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Keywords

Extreme ultraviolet, reflectometry, radiometry, scatterometry, spectroscopic ellipsometry

Citation

Tarrio, C. , Grantham, S. , Vest, R. , Germer, T. , Barnes, B. , Moffitt, S. , Simonds, B. and Spidell, M. (2023), NIST efforts in extreme-ultraviolet metrology, Proceedings of the SPIE, [online], https://doi.org/10.1117/12.2686832, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=956924 (Accessed November 21, 2024)