Using StrataGEM for Thin Film Data Processing

[UofO EPMA Lab]

We use STRATAGem* for processing our multi voltage analysis (MVA) EPMA data to obtain both composition and thickness on thin films deposited on various substrates. However, if an element is present in both the film and substrate the film thickness or composition must be specified. Multiple layers can also be accommodated.

Here is the Probe for EPMA k-ratio export window for STRATAGem* reprocessing:



Here are the results for a thin film calculation in STRATAGem*:



The document attached below will be of assistance in exporting STRATAGem* results to Excel.

More discussion on thin film analysis in PFE can be found here:

http://probesoftware.com/smf/index.php?topic=111.0

* © Copyright 1993-2016 SAMx

[Anette von der Handt]

Philip Pinard has done it again! He has created a Python-based front-end for STRATAGem.

From the webpage: "stratagemtools is a Python interface to SAMx’s STRATAGem program. The interface allows, for example, to calculate k-ratios and compute film thickness in Python using the STRATAGem’s OEM interface, i.e. without the normal graphical interface. It gives an object oriented approach to microanalysis calculations.

stratagemtools was developed as part of the doctorate thesis project of Philippe T. Pinard at RWTH Aachen University (Aachen, Germany) under the supervision of Dr. Silvia Richter."

http://stratagemtools.readthedocs.io/en/latest/

[Mike Matthews]

Can anyone tell me what the prime reference is for STRATAGem (i.e. what journal/conference was it first announced/described in)? The website says it was first released in May 1991 but the first paper after this given is a 1993 Pouchou and Pichoir paper in Scanning Microsc. Supple. 7 which I can't find on-line.

Mike

[jrminter]

I checked the StrataGem manual and it pointed to these two references describing the theory:

J.L. POUCHOU, F. PICHOIR and D. BOIVIN, Proc. ICEM 12, Seattle 1990; Microbeam Analysis, San Francisco Press, (1990), 120; ONERA Report TP 1990-109.

J.L. POUCHOU and F. PICHOIR, Electron Probe Quantitation, ed. Heinrich and Newbury, Plenum Press, New York, (1991), 31.

I also have this reference which shows an early release of the software with examples:

J. L. Pouchou, "X-ray Microanalysis of stratified specimens", Analytica Chemica Acta, 283, 81-97 (1993).

If I were to cite one, it would be the 1993 article.

Best regards,
John Minter

[Mike Matthews]

Many thanks John.

Mike

[Owen Neill]

We use STRATAGem* for processing our multi voltage analysis (MVA) EPMA data to obtain both composition and thickness on thin films deposited on various substrates. However, if an element is present in both the film and substrate the film thickness or composition must be specified. Multiple layers can also be accommodated.

Hi John,

Thanks for this very helpful primer. Had a follow-up question - I was wondering if it would be possible to set up PFE to export the StrataGEM files if the sample has multiple layers, and at least one of the layers has multiple elements? I'm working with samples that have a layer of platinum on top, a layer of tantalum oxide in the middle, and an Si wafer substrate, and I wasn't sure how to set that up with the replicate layer option (although Auerlian Moy's wonderful BadgerFilm program does allow me to set up the layers and enter the K-ratios by hand).

Thanks,
Owen

[Probeman]

What exactly are you attempting to measure?  The Ta to O ratio?

Can you define the sample as coated with Pt?  Then you'd export a Pt coated, Ta-O film and a Si substrate sample automatically.

If it's just a few samples you can also just edit the geometry in STRATAGem after importing them.

[Owen Neill]

That was my first thought (i.e. treating Pt as a coating), but the customer wants the thickness of the Pt layer, and the thickness and Ta/O ratio of the Ta-O film. So they want the Pt and TaOx treated as separate layers rather than a TaOx layer with a coating.

[Probeman]

OK, so you'll have to edit the geometry in STRATAGem (or BadgerFilm) after importing.

Remember, you'll only get the mass thickness unless you know the density of the Pt (and Ta-O) layers.

We always use critical angle XRD for film thickness determinations. More accurate than EPMA for thickness.

[Owen Neill]

Understood, should be doable. Much appreciated!