Joint analysis of the cathodoluminescence and electroluminescence spectra of SiO$_{2}$ layers on silicon

The possibility of obtaining additional information about the properties of luminescence centers by joint analysis of the electroluminescence and cathodoluminescence spectra of Si–SiO$_{2}$ structures in the spectral range of 250 – 800 nm was shown. It was found that the concentration of luminescence centers responsible for the 2.2 eV band does not depend on the final thickness of the oxide layer with a uniform distribution of centers over the SiO$_2$ thickness. It is suggested that these luminescence centers are related to equilibrium oxygen vacancies formed directly in the course of thermal oxidation. The predominant formation of luminescence centers responsible for the 4.2 eV band was revealed in the outer part of the oxide layer in an amount proportional to the square root of the thermal oxidation time, which makes it possible to associate their formation with the appearance of excess oxygen due to diffusion into the outer part of the oxide layer.