X-ray reflectivity and photoelectron spectroscopy of superlattices with silicon nanocrystals

The structural properties and features of the chemical composition of SiO$_x$N$_y$/SiO$_2$, SiO$_x$N$_y$/Si$_3$N$_4$, and SiN$_x$/Si$_3$N$_4$ multilayer thin films with ultrathin (1-1.5 nm) barrier SiO$_2$ or Si$_3$N$_4$ layers are studied. The films have been prepared by plasma chemical vapor deposition and have been annealed at a temperature of 1150$^\circ$ C for the formation of silicon nanocrystals in the SiO$_x$N$_y$ or SiN$_x$ silicon-rich layers with a nominal thickness of 5 nm. The period of superlattices in the studied samples has been estimated by X-ray reflectivity. The phase composition of superlattices has been studied by X-ray electron spectroscopy using the decomposition of photoelectron spectra of the Si 2$p$, N 1$s$, and O 1$s$ levels into components corresponding to different charge states of atoms.