General Purpose - High precision
A precision, holographic pattern providing accurate calibration in the horizontal plane for very high resolution,
nanometer-scale measurements.
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.
For 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.
For SEM, this specimen works well at all accelerating voltages. Normally supplied unmounted. Can be mounted on a stub
of your choice.
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.
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
We recommend 2D Holographic Array because of unique characteristics that make it especially easy to use. The pattern is
durable. You can scan in contact mode, which means you can calibrate and measure faster. This is the only high resolution 2D
calibration specimen we know of that has all of the following characteristics that are needed for easy 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 so that you don't have to hunt for the scan area.
AFM images:
Tapping Mode 3µm AFM scan
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Contact Mode 5µm AFM scan
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During scanning in contact mode using a 0.5 N/m SiN cantilever, we did not notice any surface or tip wear affecting the image.
Further information
SEM Images
High Magnification
The following image (inset) was captured with a magnification setting of 100 kX and accelerating voltage 10 kV. Outside Image 20 kV.
Medium Magnification
At 5 kX, the individual bumps were still well-resolved. Large fields of view show how few defects are present.
The most common defects are single missing bumps or a single extra bump inserted between lattice positions.
Two vacancies are present in the image shown here.
After completing the work, the analyst said: "It was nice to have something with sharp features."
