Chemical and phase compositions of multilayer nanoperiodic a-SiOx/ZrO2 structures subjected to high-temperature annealing

Abstract

The chemical and the phase compositions of multilayer nanoperiodic SiO_x/ZrO₂ structures prepared by vacuum evaporation from separated sources and subjected to high-temperature annealing have been studied by X-ray photoelectron spectroscopy with a layer-by-layer etching. It is found that, under deposition conditions used, the silicon suboxide layers had the stoichiometric coefficient x ~1.8 and the zirconium-containing layers were the stoichiometric zirconium dioxide. It was found, using X-ray photoelectron spectroscopy, that annealing of the multilayer structures at 1000°C leads to mutual diffusion of the components and chemical interaction between ZrO₂ and SiO_x with predominant formation of zirconium silicate at heteroboundaries of the structures. The SiO_x layers of the annealed nanostructures contained ~5 at % elemental silicon as a result of the phase separation and the formation of fine silicon nanocrystals.