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Proceedings Paper

Measurement of lithographic overlay by light-scattering ellipsometry
Author(s): Thomas A. Germer
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Paper Abstract

We demonstrate a measurement of lithographic overlay using light scattering ellipsometry. In the limit of small amplitude surface topography, the polarization of light scattered by the two interfaces of a dielectric film can be decomposed into the roughness of each interface and the complex degree of phase correlation. For two identical but offset roughness functions, the degree of phase correlation will show oscillations, whose frequency in the spatial frequency domain will be given by the overlay distance Δx. The method is tested us-ing a shallow pseudorandom binary 1-D grating, photolithographically produced on a silicon wafer and again on a spin-on glass layer deposited onto the wafer.

Paper Details

Date Published: 22 October 2002
PDF: 8 pages
Proc. SPIE 4780, Surface Scattering and Diffraction for Advanced Metrology II, (22 October 2002); doi: 10.1117/12.453789
Show Author Affiliations
Thomas A. Germer, National Institute of Standards and Technology (United States)

Published in SPIE Proceedings Vol. 4780:
Surface Scattering and Diffraction for Advanced Metrology II
Zu-Han Gu; Alexei A. Maradudin, Editor(s)

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