Multi-technique reference measurement of critical dimension and shape for model validation in scanning electron microscopy

Published

April 22, 2025

Author(s)

Wataru Yamane, Daron Westly, Glenn Holland, Yu Yamazawa, Naoto Ito, Andras Vladar, John Villarrubia

Abstract

In semiconductor device manufacturing, 3D structure measurements of newly complex devices would be valuable alongside conventional scanning electron microscopy (SEM) and critical dimension SEM (CD-SEM) measurements. Since these applications in SEM directly utilize grayscale signal intensity, accurate measurement needs a correct understanding of the physics that links intensity to structure. However, many unsolved aspects remain in SEM models. For model validation, we measured the same topography using different techniques. With e-beam lithography, we patterned line/space arrays on a thin, flat silicon membrane. We acquired images of the same features using secondary electrons in SEM and transmitted electrons in scanning transmission electron microscopy (STEM). We compared them with a subsequent image section by focused ion-beam at the same location. The determined discrepancy of line heights was 6.3 nm ± 6.1 nm. The 6.1 nm is an expanded uncertainty equal to three times the combined standard uncertainty, derived from several components that will be described. Our findings contribute to a wide range of measurements in SEM and STEM, providing insights that can potentially be useful for combined metrology in the future.

Proceedings Title

Metrology, Inspection, and Process Control XXXIX

Volume

13426

Conference Dates

February 23-27, 2025

Conference Location

San Jose, CA, US

Conference Title

SPIE Advanced Lithography + Patterning

Pub Type

Conferences

Download Paper

https://doi.org/10.1117/12.3046309

Local Download

Keywords

scanning electron microscopy (SEM), scanning transmission electron microscopy (STEM), Simulation, Scattering Models, Library based metrology, Combined metrology, Hybrid metrology

Citation

Yamane, W. , Westly, D. , Holland, G. , Yamazawa, Y. , Ito, N. , Vladar, A. and Villarrubia, J. (2025), Multi-technique reference measurement of critical dimension and shape for model validation in scanning electron microscopy, Metrology, Inspection, and Process Control XXXIX, San Jose, CA, US, [online], https://doi.org/10.1117/12.3046309, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=959651 (Accessed June 29, 2025)