Paper
22 October 2002 Measurement of lithographic overlay by light-scattering ellipsometry
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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.
© (2002) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Thomas A. Germer "Measurement of lithographic overlay by light-scattering ellipsometry", Proc. SPIE 4780, Surface Scattering and Diffraction for Advanced Metrology II, (22 October 2002); https://doi.org/10.1117/12.453789
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Cited by 1 scholarly publication and 4 patents.
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KEYWORDS
Interfaces

Light scattering

Scattering

Overlay metrology

Ellipsometry

Semiconducting wafers

Photomasks

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