Applications
- Electron microscopy - SEM, in both SE and BSE mode, SEM/FIB and TEM (with special version)
- Scanning Microscopies and Profilometry - STM, AFM, the pattern height is 70nm
- Optical Microscopy - transmitted, reflected, bright/dark field, differential contrast and confocal
- Chemical mapping - EDS, WDS, XRF, XPS, Auger and others. The pattern is fabricated using 30nm
CrO2 over 40nm Cr on quartz
- Particle Size Counting - series of circles, squares & rectangles for calibration confirmation
Pattern Design
The fifth generation MRS-4.2 is fabricated using the high accuracy direct write electron
beam manufacturing equipment.
The pattern is anti-reflective chromium (30nm Cr2O
over 40nm Cr) on quartz. Imaging in both secondary and back scattered mode is very high.
The pattern is coated with a proprietary conductive material which allows for SEM imaging
at any accelerating voltage.
Geometric design
The MRS-4 has groups of nested squares with pitches of 1/2µm, 1µm, 2µm,
50µm and 500µm. The largest pattern has an overall dimension of 8mm square with
lines and spaces of 250µm. This can be used to check magnifications between 10 - 100x.
The 50µm pitch patterns are useful from 100 - 1000x magnifications. The 2, 1 and 1/2µm
pitch patterns allow calibrations up to 200,000x. Incorporated into the standard are X &
Y rulers with 6mm length with 1µm increments.
Dimensions/Retainers
The overall size of the MRS-4 is approx. 9 x 9 x 2.3mm. Since the standard is made on
quartz, it easily chips. We highly recommend ordering the optional protective retainers
for the MRS-4.
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Optional Protective Retainer 614-5 and Optional Pin Stub Mounting 614-62
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Optical Microscope Adapter OM/R 614-6
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The standard is mounted in the retainers using an ultra high vacuum compatible, conductive
silver epoxy. There are two retainers available:
- #614-5 – SEM/R which is 25mm in diameter with a thickness of 3mm. Can be used for optical transmitted light , SE, FIB and SPM applications. Material is aluminum, Ni plated. Standard recessed: 0.5mm
- #614-6 – OM/R which is the 44.5 x 25.4 x 3.2mm optical microscope adapter, fits easily on light microscopes. Material is aluminum. Standard is slightly recessed; 0.13mm.
For the #614-5 SEM/R protective retainer can be mounted on a 25mm pin
stub as an option (order #614-62).
A special version of the MRS-4 is available for (S)TEM with a 3mm diameter and a thickness
and a thickness of 500µm. This will only show the central features and can be viewed
with secondary and backscattered electrons, not with transmitted electrons.
Accuracy
Measurements by the NPL in the UK (counterpart of NIST) have demonstrated that the accuracy of
the 500µm was ±0.25µm, and ± 0.1µm for the 50µm and 2µm
patterns. The 1µm and 1/2µm patterns have an accuracy of ±0.04µm.
Certification report
The certification is done following ISO guidelines. Each MRS-4 has a unique serial number
engraved on the standard. Certification includes the serial number, certification date,
operator, instrumentation used, actual pattern measurements and measure of accuracy.
NIST = National Institute of Standards and Technology, USA
NPL = National Physical Laboratories, UK (counterpart of NIST)