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Measurement of Lithographic Overlay by Light-Scattering Ellipsometry

Published

Author(s)

Thomas A. Germer

Abstract

We demonstrate a measurement of lithographic overlay using light scattering ellipsometry. In the limit of small amplitude surfactopography, the polarization of light scattered by the two interfaces of a dielectric film can be decomposed into the roughness oeach interface and the complex degree of phase correlation. For two identical but offset roughness functions, the degree of phascorrelation will show oscillations, whose frequency in the spatial frequency domain will be given by the overlay distance Ax. Thmethod is tested using a shallow pseudorandom binary 1-D grating, photolithographically produced on a silicon wafer and agaon a spin-on glass layer deposited onto the wafer.
Proceedings Title
Surface Scattering and Diffraction for Advanced Metrology, Conference | 2nd | Surface Scattering and Diffraction for Advanced Metrology II | SPIE
Conference Dates
July 7-11, 2002
Conference Title
Proceedings of SPIE--the International Society for Optical Engineering

Keywords

Ellipsometry, films, lithography, overlay, roughness, scattering, topography

Citation

Germer, T. (2002), Measurement of Lithographic Overlay by Light-Scattering Ellipsometry, Surface Scattering and Diffraction for Advanced Metrology, Conference | 2nd | Surface Scattering and Diffraction for Advanced Metrology II | SPIE (Accessed June 19, 2024)

Issues

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Created September 1, 2002, Updated February 17, 2017