Nanoscale potential fluctuations in SiO$_{x}$ synthesized by the plasma enhanced chemical vapor deposition

The atomic structure and electron spectrum of $a$-SiO$_{x}$:H films deposited on silicon and glass substrates by the plasma enhanced chemical vapor deposition method are considered in this paper. The film stoichiometric parameter $x$ varied in the range from 0.57 to 2 depending on the oxygen supply to the reactor conditions. The film structures and the electronic structure peculiarities characterization, depending on the parameter $x$ value, were carried out using a set of structural and optical techniques, as well as the ab initio quantum-chemical simulation for the model SiO$_x$ structure. It was established that the studied SiO$_x$:H films mainly consist of silicon suboxide SiO$_y$ with SiO$_2$ and amorphous Si clusters. Based on the spatial chemical composition fluctuations, the electron and hole potential fluctuations model for SiO$_{x}$ is proposed. The obtained results will allow a more accurate charge transport modeling in $a$-SiO$_x$:H films, which is important for creating nonvolatile memory and memristor elements on the base of SiO$_{x}$.