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Article
Infrared Optical Properties of Amorphous and Nanocrystalline Ta2O5 Thin Films
Journal of Applied Physics
  • Trevor J. Bright, Georgia Institute of Technology
  • J. I. Watjen, Georgia Institute of Technology
  • Zhuomin Zhang, Georgia Institute of Technology
  • Christopher Muratore, University of Dayton
  • Andrey A. Voevodin, Air Force Research Laboratory
  • D. I. Koukis, University of Florida
  • David B. Tanner, University of Florida
  • Daniel J. Arenas, University of North Florida
Document Type
Article
Publication Date
1-1-2013
Abstract
The optical constants of tantalum pentoxide (Ta 2O5) are determined in a broad spectral region from the visible to the far infrared. Ta 2O5 films of various thicknesses from approximately 170 to 1600 nm aredeposited using reactive magnetron sputtering on Si substrates. X-ray diffraction shows that the as-deposited films are amorphous, and annealing in air at 800 °C results in the formation of nanocrystallineTa 2O5. Ellipsometry is used to obtain the dispersion in the visible and near-infrared. Two Fourier-transform infrared spectrometers are used to measure the transmittance and reflectance at wavelengths from 1 to 1000 μm. The surface topography and microstructure of the samples are examined using atomic force microscopy, confocal microscopy, and scanning electron microscopy. Classical Lorentz oscillatorsare employed to model the absorption bands due to phonons and impurities. A simple model is introduced to account for light scattering in the annealed films, which contain micro-cracks. For the unannealed samples, an effective-medium approximation is used to take into account the adsorbed moisture in the film and a Drude free-electron term is also added to model the broad background absorption.
Inclusive pages
083515-1 to 083515-10
ISBN/ISSN
0021-8979
Document Version
Published Version
Comments

This document is provided for download in compliance with the publisher's policy on self-archiving. Permission documentation is on file.

Publisher
AIP Publishing
Peer Reviewed
Yes
Citation Information
Trevor J. Bright, J. I. Watjen, Zhuomin Zhang, Christopher Muratore, et al.. "Infrared Optical Properties of Amorphous and Nanocrystalline Ta2O5 Thin Films" Journal of Applied Physics Vol. 114 (2013)
Available at: http://works.bepress.com/christopher-muratore/32/