In situ characterization of stoichiometry for the buried SiOx layers in SiOx/SiO2 superlattices and the effect on the photoluminescence property

The stoichiometry of SiOx layers in SiOx/SiO2 superlattice (SL) films grown by ion beam sputtering method was determined with in situ X-ray photoelectron spectroscopy. The effect of oxygen content on the photoluminescence (PL) properties was studied for the bulk-SiOx films and SiOx/SiO2 SLs. Maximum PL intensities were observed near x≈1.6 and x≈1.2 for the bulk-SiOx films and SiOx/SiO2 SLs, respectively. However, the dependence of PL intensity and energy on the film stoichiometry, when scaled for the overall film stoichiometry, was nearly the same for the bulk-SiOx films and SiOx/SiO2 SLs. This result indicates that the oxygen content is the main parameter to determine PL property of the SiOx/SiO2 SLs.