PROPERTIES OF ANODIC-OXIDIZED SILICON FILMS IMPLANTED WITH HIGH DOSES OF CO+ IONS
I. E. Tyschenko, E. V. Spesivtsev, Z. V. Smagina, I. V. Popov, V. P. Popov
Rzhanov Institute of Semiconductor Physics, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
Keywords: Silicon, SiO, CO, Ion implantation, Anodic oxidation, Microcavities
Abstract
The properties of the anodic oxidized Si layers implanted with CO+ ions at an energy of 90 keV to were studied as a function of ion dose ranging from 2.5x1015 to 3x1016 cm-2. After the implantation, the samples were annealed at 700 oC for 1 hour in the N2 ambient. Spectral ellipsometry, atomic force microscopy and Fourier transform infrared spectroscopy were employed to study the oxidized layers. The refractive index of oxidized layers was higher than that in the thermally oxidized SiO2 and dropped from 1.58 to 1.52 as the ion dose increased from 2.5x1015 to 1x1016 cm-2. As the ion dose increased, the absorption band corresponding to the optical absorption by CO2 molecules grew. The refractive index of the anodic oxidized layers as a function of ion dose is discussed in the frame of the microcavity formation in the SiO2 as result of CO2 molecules evaporation.
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