X-ray photoelectron study of the effect of the composition of the initial gas phase on changes in the electronic structure of hexagonal boron nitride films obtained by PECVD from borazine

Hexagonal boron nitride films are synthesized by plasma enhanced chemical vapor deposition (PECVD) from a gas mixture of borazine and ammonia or helium on Si(100) substrates. X-ray photoelectron spectroscopy is used to study changes in the electronic structure and chemical composition of the films depending on the composition of the initial gas mixture. It is found that the chemical composition of the samples depends on the gas used. The use of helium results in an excess of boron atoms on the film surface, the appearance of B–B bonds, and a decrease in the contribution of B–N bonds in the hexagonal structure. The preparation of h-BN films close to the stoichiometric composition by PECVD methods with the use of borazine is shown to be possible with the addition of ammonia. Based on the literature data, the binding energies in the B 1s XPS spectra are calculated for different boron environments in the hexagonal lattice.