Eur. Phys. J. Appl. Phys.
Volume 42, Number 3, June 2008
|Page(s)||351 - 359|
|Section||Instrumentation and Metrology|
|Published online||04 June 2008|
Critical dimension of biperiodic gratings determined by spectral ellipsometry and Mueller matrix polarimetry
Laboratoire de Physique des Interfaces et Couches Minces, UMR 7647, École Polytechnique, 91128 Palaiseau Cedex, France
2 CEA LETI – MINATEC, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France
3 Department of Physics, Technical University of Ostrava, 17. listopadu 15, 70833 Ostrava, Czech Republic
Corresponding author: firstname.lastname@example.org
Revised: 28 January 2008
Accepted: 2 April 2008
Published online: 4 June 2008
We characterized two samples consisting of photoresist layers on silicon with square arrays of square holes by spectroscopic ellipsometry (SE) and Mueller matrix polarimetry (MMP). Hole lateral dimensions and depths were determined by fitting either SE data taken in conventional planar geometry or MMP data in general conical diffraction configurations. A method for objective determination of the optimal measurement conditions based on sensitivity and parameter correlations is presented. When applied to MMP, this approach showed that for one of the samples the optimal incidence angle was 45°, much below the widely used 70° value. The robustness of the dimensional characterisation based on MMP is demonstrated by the high stability of the results provided by separated fits of the data taken at different azimuthal angles.
PACS: 42.79.Dj – Gratings / 07.60.Fs – Polarimeters and ellipsometers / 95.75.Hi – Polarimetry / 42.62.Eh – Metrological applications; optical frequency synthesizers for precision spectroscopy
© EDP Sciences, 2008
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