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Publication Citation: Intermittent-Contact Scanning Capacitance Microscope for Lithographic Overlay Measurement

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Author(s): Joseph J. Kopanski; Santos D. Mayo;
Title: Intermittent-Contact Scanning Capacitance Microscope for Lithographic Overlay Measurement
Published: May 11, 1998
Abstract: A new scanning capacitance microscope (SCM) mode was implemented by using an atomic force microscope (AFM) operated in intermittent contact and by measuring the tip-to-sample capacitance change at the tip vibration frequency. The intermittent-contact-mode SCM was able to image and determine the overlay separation of metal lines buried under an 1 [mu]m thick, planarized dielectric layer. Modeling of the intermittent-contact SCM signal across buried metal lines was consistent with the experimental results. This hybrid intermittent-contact AFM and SCM has the potential to measure the lithographic overlay between metal lines located at consecutive levels beneath dielectric layers in an integrated circuit.
Citation: Applied Physics Letters
Volume: 72
Issue: 19
Pages: pp. 2469 - 2471
Keywords: atomic force microscopy;buried line imaging;overlay metrology;
Research Areas: