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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.
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 October 2, 2025)