Overlay measurement using angular scatterometer for the capability of integrated metrology

Angular scatterometry, which has the advantage of good measurement precision, is an optical measurement technology based on the analysis of light scattered from periodic features, such as a linear grating, and is proposed as an alternative solution for overlay metrology. We present overlay measureme...

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Bibliographic Details
Published in:Optics express 2006-06, Vol.14 (13), p.6001-6010
Main Authors: Ko, Chun-Hung, Ku, Yi-Sha
Format: Article
Language:English
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Summary:Angular scatterometry, which has the advantage of good measurement precision, is an optical measurement technology based on the analysis of light scattered from periodic features, such as a linear grating, and is proposed as an alternative solution for overlay metrology. We present overlay measurements using an angular scatterometer and a bright-field microscope. A theoretical library based on rigorous coupled wave theory was created, and the reflected signatures measured by angular scatterometer were matched to the library to obtain structure parameters, including overlay, critical dimension (CD), and sidewall angle at the same time. The results reveal that angular scatterometer has a good precision and low tool-induced shift for overlay measurements, and has the potential for integrated metrology.
ISSN:1094-4087
1094-4087
DOI:10.1364/OE.14.006001