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M. Horkel, H. Mahr, J. Hell, E. Neubauer:
"Spatially Resolved Thickness Determination Of Metal And Oxide Coatings Using Optical Consumer Electronic Components";
Vortrag: 14th International Conference on Thin Films & Reactive Sputter Deposition, Ghent, Belgien; 17.11.2008 - 20.11.2008.

Film thickness determination by optical methods is an established and well known field. A huge variety of high precision optical instruments, ranging from spectro-photometers via confocal microscopes to spectroscopic ellipsometers are commercially available.
On the other hand, in recent years also the sector of consumer electronics begins to offer high precision optical instruments such as digital cameras and high resolution scanners at very low costs.
This paper describes the use of consumer electronic components to determine the thickness of metallic and dielectric coatings in the nm range by using easily available consumer electronic components. Two examples are presented:
(i) Thickness determination of Mo coatings on Diamond granulates: Industrial diamonds with grain sizes of 50 - 200 µm were uniformly coated with molybdenum by DC magnetron sputtering in a specially designed mixing device. The Mo thickness was determined by the measurement of optical density using a Reflecta CrystalScan 7200 optical scanner working in transmission mode with Silverfast AFL-SE software. A good match with the film thicknesses calculated from the deposition time and the known erosion rate of the sputter source was achieved.
(ii) Transparent coatings of Al-oxide with variable thickness were deposited on natively oxidized Si wafers. The thickness variation leads to the formation of interference patterns with a lateral extension of some centimetres. The interference patterns were imaged by a digital camera (OLYMPUS MJU 760) and quantitatively evaluated at three different wavelengths using RGB-splitting. The film thicknesses obtained from the interferometric measurements were compared to profilometric measurements and found to be in good agreement
These two examples show that quite demanding tasks related to film thickness determination may be executed with high accuracy by present day consumer electronic devices.
The financial support of the Austrian "Fonds zur Förderung der Wissenschaftlichen Forschung" (FWF), Grant No. P-19379-N16 and the IWT Flanders, Grant No. SBO-060030 is gratefully acknowledged.