Optical Properties of Nonstoichiometric Tantalum Oxide TaOx (x < 5/2) According to Spectral-Ellipsometry and Raman-Scattering Data
- Authors: Kruchinin V.N.1, Volodin V.A.1,2, Perevalov T.V.1,2, Gerasimova A.K.1, Aliev V.S.1, Gritsenko V.A.1,2,3
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Affiliations:
- Rzhanov Institute of Semiconductor Physics, Siberian Branch
- Novosibirsk State University
- Novosibirsk State Technical University
- Issue: Vol 124, No 6 (2018)
- Pages: 808-813
- Section: Condensed-Matter Spectroscopy
- URL: https://bakhtiniada.ru/0030-400X/article/view/165720
- DOI: https://doi.org/10.1134/S0030400X18060140
- ID: 165720
Cite item
Abstract
Optical properties of amorphous nonstoichiometric tantalum-oxide films of variable composition (TaOx, x = 1.94–2.51) in the spectral range of 1.12–4.96 eV, obtained by ion-beam sputtering-deposition of metallic tantalum at different partial oxygen pressures (0.53–9.09 × 10–3 Pa), have been investigated. It is shown by spectral ellipsometry that the character of dispersion of the absorption coefficient and refractive index in TaOx of variable composition suggests that light-absorbing films with dispersion similar to that in metals are formed at oxygen pressures in the growth chamber below 2.21 × 10–3 Pa, whereas transparent films with dielectric dispersion are formed at pressures above 2.81 × 10–3 Pa. According to the data of quantumchemical simulation, the absorption peak at a photon energy of 4.6 eV in TaOx observed in the absorptioncoefficient dispersion spectrum is due to oxygen vacancy. The peak in the Raman-scattering spectra of TaOx films with metallic dispersion at frequencies of 200–230 cm–1 is presumably related to tantalum nanoclusters.
About the authors
V. N. Kruchinin
Rzhanov Institute of Semiconductor Physics, Siberian Branch
Author for correspondence.
Email: kruch@isp.nsc.ru
Russian Federation, Novosibirsk, 630090
V. A. Volodin
Rzhanov Institute of Semiconductor Physics, Siberian Branch; Novosibirsk State University
Email: kruch@isp.nsc.ru
Russian Federation, Novosibirsk, 630090; Novosibirsk, 630090
T. V. Perevalov
Rzhanov Institute of Semiconductor Physics, Siberian Branch; Novosibirsk State University
Email: kruch@isp.nsc.ru
Russian Federation, Novosibirsk, 630090; Novosibirsk, 630090
A. K. Gerasimova
Rzhanov Institute of Semiconductor Physics, Siberian Branch
Email: kruch@isp.nsc.ru
Russian Federation, Novosibirsk, 630090
V. Sh. Aliev
Rzhanov Institute of Semiconductor Physics, Siberian Branch
Email: kruch@isp.nsc.ru
Russian Federation, Novosibirsk, 630090
V. A. Gritsenko
Rzhanov Institute of Semiconductor Physics, Siberian Branch; Novosibirsk State University; Novosibirsk State Technical University
Email: kruch@isp.nsc.ru
Russian Federation, Novosibirsk, 630090; Novosibirsk, 630090; Novosibirsk, 630073
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