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Recent Developments in Producing Test-structures for Use as Critical Dimension Reference Materials



Richard A. Allen, Ravi I. Patel, Michael W. Cresswell, Christine E. Murabito, Brandon Park, Monica D. Edelstein, Loren W. Linholm


NIST is developing Single-Crystal Critical-Dimension Reference Materials (SCCDRM) which address the need of the semiconductor and semiconductor equipment industries for a well-characterized artifact to serve as the basis for comparing the performance of different classes of CD measurement instruments. Recent work has focused on providing an integrated process that can be transferred to a production environment. The two remaining issues were identified as key to successful completion of the project. The first is providing sufficiently narrow features (where 'sufficiently narrow' is defined as much narrower than those required last year). The second is ensuring that the set of structures imaged are optimal for the calibration as well as reducing time and expense of the high-resolution transmission electron microscopy (HRTEM) imaging. In this paper we discuss recent work to address these two issues. For the first, a process was developed to reduce the linewidths of silicon features, on selected chips, to the desired dimensions. The modified process adds a sequence of three wet etches to reduce the overall width of the replicated features while enabling them to retain their essential cross-section rectangularity and sidewall flatness. In this paper we describe this modification and present initial results. To address the issues associated with the HRTEM step, a new test structure was developed which incorporates a set of different width features in a way that allows optimal evaluation of the features using several imaging techniques, with an emphasis on optimizing the HRTEM imaging, which is the most time-consuming and expensive of the imaging techniques used.
Conference Dates
March 22-25, 2004
Conference Location
Awaji Island, 1, JA
Conference Title
ICMTS IEEE International Conference on Microelectronic Test Structures


anisotropic etch, critical dimension, electrical test structure, high-resolution transmission electron microscopy, reference material


Allen, R. , Patel, R. , Cresswell, M. , Murabito, C. , Park, B. , Edelstein, M. and Linholm, L. (2004), Recent Developments in Producing Test-structures for Use as Critical Dimension Reference Materials, ICMTS IEEE International Conference on Microelectronic Test Structures, Awaji Island, 1, JA (Accessed July 17, 2024)


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Created February 29, 2004, Updated October 12, 2021