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Photomask Linewidth Comparison by PTB and NIST



Detleff Bergmann, Bernd Bodermann, Harald Bosse, Egbert Buhr, Gaoliang Dai, Ronald G. Dixson, W H?er-Grohne


We report the initial results of a recent bilateral comparison of linewidth or critical dimension (CD) calibrations on photo-mask line features between two national metrology institutes (NMIs): the National Institute of Standards and Technology (NIST) in the United States and the Physikalisch-Technische Bundesanstalt (PTB) in Germany. For the comparison, a chrome on glass (CoG) photomask was used which has a layout of line features down to 100 nm nominal size. Different measurement methods were used at both institutes. These included: critical dimension atomic force microscopy (CD-AFM), CD scanning electron microscopy (CD-SEM) and ultraviolet (UV) transmission optical microscopy. The measurands are CD at 50 % height of the features as well as sidewall angle and line width roughness (LWR) of the features. On the isolated opaque features, we found agreement of the CD measurements at the 3 nm to 5 nm level on most features - usually within the combined expanded uncertainties of the measurements.
Proceedings Title
SPIE Proceedings: Scanning Microscopies 2015
Conference Dates
September 29-October 1, 2015
Conference Location
Monterey, CA, US
Conference Title
Scanning Microscopies 2015


linewidth, CD metrology, uncertainty components, Nano1, international comparison, MRA, photomask


Bergmann, D. , Bodermann, B. , Bosse, H. , Buhr, E. , Dai, G. , Dixson, R. and H?er-Grohne, W. (2015), Photomask Linewidth Comparison by PTB and NIST, SPIE Proceedings: Scanning Microscopies 2015, Monterey, CA, US, [online], (Accessed April 15, 2024)
Created November 1, 2015, Updated October 12, 2021