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Preparation and characterization of tantalum oxide films produced by reactive DC magnetron sputtering

2003; Wiley; Volume: 198; Issue: 1 Linguagem: Inglês

10.1002/pssa.200306444

1521-396X

James M. Ngaruiya, Selvaraj Venkataraj, R. Drese, Oliver Kappertz, T. P. Leervad Pedersen, Matthias Wuttig,

ZnO doping and properties

physica status solidi (a)Volume 198, Issue 1 p. 99-110 Original Paper Preparation and characterization of tantalum oxide films produced by reactive DC magnetron sputtering J. M. Ngaruiya, J. M. Ngaruiya I. Physikalisches Institut der RWTH Aachen, 52056 Aachen, Germany Jomo Kenyatta University of Agric. & Techn., Box 62000, Nairobi, KenyaSearch for more papers by this authorS. Venkataraj, S. Venkataraj I. Physikalisches Institut der RWTH Aachen, 52056 Aachen, GermanySearch for more papers by this authorR. Drese, R. Drese I. Physikalisches Institut der RWTH Aachen, 52056 Aachen, GermanySearch for more papers by this authorO. Kappertz, O. Kappertz I. Physikalisches Institut der RWTH Aachen, 52056 Aachen, GermanySearch for more papers by this authorT. P. Leervad Pedersen, T. P. Leervad Pedersen I. Physikalisches Institut der RWTH Aachen, 52056 Aachen, GermanySearch for more papers by this authorM. Wuttig, Corresponding Author M. Wuttig wuttig@physik.rwth-aachen.de I. Physikalisches Institut der RWTH Aachen, 52056 Aachen, Germany ISG3, Forschungszentrum Jülich, 52428 Jülich, Germany Tel: (49)241 80 27155, Fax: (49)241 80 22331Search for more papers by this author J. M. Ngaruiya, J. M. Ngaruiya I. Physikalisches Institut der RWTH Aachen, 52056 Aachen, Germany Jomo Kenyatta University of Agric. & Techn., Box 62000, Nairobi, KenyaSearch for more papers by this authorS. Venkataraj, S. Venkataraj I. Physikalisches Institut der RWTH Aachen, 52056 Aachen, GermanySearch for more papers by this authorR. Drese, R. Drese I. Physikalisches Institut der RWTH Aachen, 52056 Aachen, GermanySearch for more papers by this authorO. Kappertz, O. Kappertz I. Physikalisches Institut der RWTH Aachen, 52056 Aachen, GermanySearch for more papers by this authorT. P. Leervad Pedersen, T. P. Leervad Pedersen I. Physikalisches Institut der RWTH Aachen, 52056 Aachen, GermanySearch for more papers by this authorM. Wuttig, Corresponding Author M. Wuttig wuttig@physik.rwth-aachen.de I. Physikalisches Institut der RWTH Aachen, 52056 Aachen, Germany ISG3, Forschungszentrum Jülich, 52428 Jülich, Germany Tel: (49)241 80 27155, Fax: (49)241 80 22331Search for more papers by this author First published: 19 May 2003 https://doi.org/10.1002/pssa.200306444Citations: 48AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Abstract We report on the influence of oxygen flow rate on structure, composition, density, deposition stress and optical properties of the as-deposited tantalum oxide thin films. The films were prepared by reactive direct current magnetron sputtering. The sputter current and total pressure were kept constant at 300 mA and 0.8 Pa, respectively. We could deposit fully transparent films at a rate of approximatey 6 nm/min. without noticeable substrate warming from the plasma. Grazing angle XRD showed the films to be amorphous at all oxygen flow rates. Simulations to RBS data revealed, within errors, stoichiometric films above 2 sccm oxygen flow. Moreover argon incorporation in the films above 2 sccm oxygen flow was noted. The density was found to steeply decrease upto 2 sccm followed by a very slow linear decrease with oxygen flow as deduced from X-ray reflectometry. The refractive index, the extinction coefficient and the band gap energy were all obtained by optical spectroscopy. A band gap which increased from 4.17 to 4.23 eV with oxygen flow was determined for films in the transparent region. A characteristic of the defects in the film, γ, which is obtained by simulating the optical spectra, was found to decrease from 85 meV at 6 sccm to 60 meV at 15 sccm oxygen flow. There was no significant change in γ above 15 sccm. On the other hand the refractive index and the extinction coefficient were found to slightly decrease with increasing oxygen flow for the transparent films. Stress data revealed the films to be under some compressive stress upon deposition. The stress decreased with increasing oxygen flow and stabilized at roughly –250 MPa above 6 sccm oxygen flow. Citing Literature Volume198, Issue1July 2003Pages 99-110 RelatedInformation