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Critical Dimension and Overlay Metrology



Michael T. Postek, Marylyn H. Bennett


Critical dimension and overlay metrology are two of the important measurements made in semiconductor device fabrication. Critical dimension metrology is important to ensure that the product meets the design target and overlay metrology ensures correct alignment of the various layers composing the device. Where semiconductor metrology research is concerned, the role of NIST, in this case, is to develop the infrastructural metrology and standards for these semiconductor industry applications. NIST has been involved with critical dimension metrology since the early work on photomask metrology began in the 1970s and over the years has produced a series of accurate optical photomask standards. Because of the nanometer sizes of devices in current semiconductor production, wafer CD metrology is currently being pursued with scanning electron beam instrumentation commonly called the CD-SEM, since this is currently the most common tool used in the industry for this purpose, Scanned probe instrumentation is also being explored for accurate metrology, as well as electrical metrology. Standards and metrology methodology for optical overlay metrology are now being used by the industry and a move to scanned electron beam metrology may be in the offing. This presentation highlights some of the projects have been developed closely with International SEMATECH for the efficient bi-directional transfer of meterology technology from NIST to industry and the transfer of the pressing industrial needs form industry to NIST.
Proceedings Title
Proceedings of GOMACTech Conference
Conference Dates
March 31-April 3, 2003
Conference Location
Tampa, FL
Conference Title
GOMACTech Conference


critical dimensions, linewidth, metrololgy, overlay, telepresence, TIS, WIS


Postek, M. and Bennett, M. (2003), Critical Dimension and Overlay Metrology, Proceedings of GOMACTech Conference, Tampa, FL (Accessed July 25, 2024)


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Created March 1, 2003, Updated February 19, 2017