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Publications in Scientific Journals:

F. Bammer, R. Petkovsek, J. Petelin, J. Mozina:
"Fast ellipsometric measurements based on a single crystal photo-elastic modulator";
Optics Express, 18 (2010), 20; 21410 - 21418.



English abstract:
For quality control in high volume manufacturing of thin layers and for tracking of physical and chemical processes, ellipsometry is a common measurement technology. For such kinds of applications we present a novel approach of fast ellipsometric measurements. Instead of a conventional setup that uses a standard photo-elastic modulator, we use a 92 kHz Single Crystal Photo-Elastic Modulator (SCPEM), which is a LiTaO3 crystal with a size of 28 × 9 × 4 mm. This small, simple, and cost-effective solution also offers the advantage of direct control of the retardation via the current amplitude, which is important for repeatability of the measurements. Instead of a Lock-In Amplifier, an automated digital processing based on a fast analog to digital converter controlled by a highly flexible Field Programmable Gate Array is used. This and the extremely compact and efficient polarization modulation allow fast ellipsometric testing where the upper limit of measurement rates is mainly limited by the desired accuracy and repeatability of the measurements. The standard deviation that is related to the repeatability +/-0.002° for dielectric layers can be easily reached.

German abstract:
Realisierung eines schnellen Ellipsometer basierend auf einem Photo-Elastischen Einkristallmodulator

Keywords:
Modulators, Ellipsometry and polarimetry, Ellipsometry and polarimetry, Ellipsometry and polarimetry, Photo-elastic modulators


"Official" electronic version of the publication (accessed through its Digital Object Identifier - DOI)
http://dx.doi.org/10.1364/OE.18.021410

Electronic version of the publication:
http://publik.tuwien.ac.at/files/PubDat_190572.pdf


Created from the Publication Database of the Vienna University of Technology.