The Nanoscale World

Accuracy of calibration grids

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Top 75 Contributor
13 Posts
Points 146
Alessandro Podestà posted on Thu, Jun 6 2013 4:01 AM

(I post this message on the Forum, previously, and uncorrectly, published as announcement)

 

Hi all,
I have three calibration grids from Digital Instruments/Veeco/Bruker and I would like to know what reasonably are the relative x,y,z accuracies of these specimens (these are not NIST certified samples, nevertheless it should be possible, based on the way they are produced, to assess reasonably accurate accuracy figures).

Unfortunately, I do not have specification documents for the three objects, and I could only find uncomplete or unclear information browsing around the web; so I ask the community for helping me. I have always attributed a rather arbitrary 2% accuracy to the calibration perfrmed using these gratings.

I report below what is written on the calibration grid packages.

Many thanks and best regards
Alessandro Podesta'

-----------------------------
Sample #1 (provided by Veeco 5 years ago)
Digital Instruments
10 um pitch
200 nm deep
3D reference
P/N 498-000-026
NGR-11010-F120
NanoDevices

Sample #2 (provided by Veeco 5 years ago)
Digital Instruments/Veeco Metrology Group
PG
Platinum Coated
Calibration Grid
1um x 1um Period

Sample #3 (provided by DI when our Multimode was installed > 10 years ago....)
The original box has been lost.
Specs are:
Pitch 10 um
Pits 180 nm
could it be the STR10−1800P model ?

Alessandro Podestà, PhD
Dept. of Physics and CIMAINA,
Università degli Studi di Milano
via Celoria 16 - 20133 MILANO, Italy
E-mail: alessandro.podesta@mi.infn.it
Web: http://www.mi.infn.it/~podesta/
Res.ID: http://www.researcherid.com/rid/E-6568-2010
ORCID: https://orcid.org/0000-0002-4169-6679
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Top 25 Contributor
35 Posts
Points 381

Hi Alessandro,

I would be grateful for sharing that information with me too.

In the meantime, you could try the autocorrelation of your sample by shifting it along one of the axis and measuring the errors produced by the instrument. That will give you an idea on the accuracy of your instrument as well as the accurate measurements of your samples. With those figures in hands, you would decide on what is critical for your experiments: scanner non-linearity or the calibration sample accuracy.

You would probably remember the metrological principles of calibration. One of the critical factors is that the calibrated scanning area and offset must correspond to the actual measurement conditions of your sample of interest.

Some more ideas can be found here:
http://confocal-manawatu.pbworks.com/w/page/45307622/Nyquist%20Sampling%20for%20non-CD%20Imaging

I hope that worked for you.

Cheers,
Dmitry

 

  • | Post Points: 12
Top 75 Contributor
13 Posts
Points 146

Dear Dmitry,
thank you for your message.
I will try to apply autocorrelation analysis and look at the link you suggest.

I'll forward to you any information I will receive on gratings specs.

Best regards,
Alessandro

Alessandro Podestà, PhD
Dept. of Physics and CIMAINA,
Università degli Studi di Milano
via Celoria 16 - 20133 MILANO, Italy
E-mail: alessandro.podesta@mi.infn.it
Web: http://www.mi.infn.it/~podesta/
Res.ID: http://www.researcherid.com/rid/E-6568-2010
ORCID: https://orcid.org/0000-0002-4169-6679
  • | Post Points: 10
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