Period: 144nm pitch, two-dimensional array. Accurate to ±1nm. Refer to calibration certificate for actual pitch.
Surface: Aluminum bumps on Silicon, 4x3mm die. Bump height (about 90nm) and width (about 75nm) are not calibrated.
Usability: the calibrated pattern covers the entire chip. There is sufficient usable area to make tens of thousands of measurements without reusing any areas altered or contaminated by previous scans.
AFM: use in contact, intermittent contact (TappingMode™ ) and other modes with image sizes from 250nm to 10mm. Available unmounted or mounted on 12mm steel disks.
SEM: this specimen works well at all accelerating voltages. Normally supplied unmounted. Can be mounted on a stub of your choice.
Model 2D: This Calibration Reference specimen comes with a non-traceable, manufacturer’s certificate. This states the average period, based on batch measurements.
Model 2DUTC: This Traceable, Certified Standard is a select grade. Each standard is individually measured in comparison with a similar specimen calibrated at PTB. (PTB, Physikalisch-Technischen Bundesanstalt, is the German counterpart of NIST.) The uncertainty of single pitch values is typically ±1.4nm (95% confidence interval). Multi-pitch measurements provide the usual square-root of N improvement in precision.
Easy to use

The 2D holographic Array with 144nm is recommended because of the unique characteristics that make it especially easy to use. The pattern is durable and allows for scanning in contact mode, which means that calibration and measurements are faster. This is the only high resolution 2D calibration standard we know of that has all of the following characteristics that are needed for ease of use:

2-dimensional array for simultaneous calibration of X and Y axes
pitch << 500nm
array of bumps means the image contrast is high even when the probe tip is slightly dull
high contrast in contact mode scans
pattern covers the entire die, no need to hunt for the scan area