Luminescence of Oxide Films Obtained by Atomic Layer Deposition

Abstract

The possibilities of the luminescence method for studying Si–oxide and Si–SiO₂–oxide structures have been demonstrated. A model of the electronic structure of Ta₂O₅ and TiO₂ layers is proposed, which explains the shape of the spectral luminescence distribution independent of the excitation way. A comparison of the luminescence spectra of single oxide layers with the spectrum of Si–SiO₂–oxide structures made it possible to draw conclusions about the interaction between layers during layered structure formation and estimate the band gap: 4.4 and 3.3 eV for Ta₂O₅ and TiO₂, respectively. The formation of Ta₂O₅ on the SiO₂ surface led to transformation in the SiO₂ surface region, manifesting itself in weakening of the luminescence band at 1.9 eV and formation of defects (luminescence centers) in the vicinity of 3 eV. Synthesis of TiO₂ on the surface of SiO₂ was not accompanied by any changes in the luminescence spectra.