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Comparison of line width calibration using critical dimension atomic force microscopes between PTB and NIST



Gaoliang Dai, Kai Hahm, Harald Bosse, Ronald G. Dixson


International comparisons between National Metrology Institutes (NMIs) are important to verify measurement results and the associated uncertainties. In this paper, we report a comparison of the line width calibration of a crystal silicon line width standard, referred to as IVPS100-PTB standard, between the Physikalisch-Technische Bundesanstalt (PTB) in Germany and the National Institute of Standards and Technology (NIST) in the United States. Critical Dimension Atomic Force Microscopy (CD-AFM) was the measurement method used for this comparison. Both institutes applied generally the same but independently developed traceability pathway: The scaling factor of the atomic force microscope (AFM) scanner was calibrated by a set of step height and lateral standards certified by metrological AFMs, while the effective tip width was ultimately traceable to the crystal silicon lattice constant via High Resolution Transmission Electron Microscopy (HR-TEM). Good agreement has been achieved in the comparison: for two groups of line features with nominal critical dimensions (CDs) of 50 nm, 70 nm, 90 nm, 110 nm and 130 nm compared, the deviation of CD results lies between -1.5 nm … 0.3 nm. All En values of the comparison are well below 1, indicating that the deviations are well within the associated measurement uncertainty.
Measurement Science & Technology


Critical Dimension, linewidth, metrology, CD-AFM, tip calibration, standards, traceability, international comparison


Dai, G. , Hahm, K. , Bosse, H. and Dixson, R. (2017), Comparison of line width calibration using critical dimension atomic force microscopes between PTB and NIST, Measurement Science & Technology (Accessed July 15, 2024)


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Created April 18, 2017, Updated October 12, 2021