Characterization of Oblique Deposited Nanostructured SiO_x Films by Ellipsometric and IR Spectroscopies

Abstract:

Studies of oblique deposited nanostructured SiOx films by ellipsometric and IR spectroscopies are presented, as additional information is obtained by scanning electron microscopy (SEM). The films were deposited onto Si substrates under a 75° incidence vapor by vacuum evaporation of SiO and were annealed in Ar at 950oC. The thickness and composition of the films were estimated from the ellipsometric data analysis applying the Bruggeman effective approximation theory. Three-layer optical model described satisfactory the annealed film structure and verified the formation of nanocrystalline Si clusters. SEM micrographs showed that evaporated films consisted of silicon oxide pillars separated by air space and tilted at an angle of ~57o to Si substrate surface. The thin silica pillars were most probably free from Si-SiO2 interface leading to absence of strong absorption on LO vibrations in the IR spectrum. The estimated porosity factor was ~62 %. By annealing, the film oxidized to SiO2 but it remained columnar with a porosity factor of ~47 %.

• Periodical: Solid State Phenomena (Volume 159)
• Pages: 149-152
• DOI: https://doi.org/10.4028/www.scientific.net/SSP.159.149
• Online since: January 2010
• Authors: A. Szekeres, E. Vlaikova, T. Lohner, Attila Lajos Tóth, I.P. Lisovskyy, S.O. Zlobin, P.E. Shepeliavyi
• Keywords: Infrared Spectroscopy, Nano-Sized Si Cluster, Scanning Electron Microscope (SEM), Silicon Oxide (SiO), Spectroscopic Ellipsometry (SE), Vacuum Evaporation

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