Oxygen reaction-diffusion in metalorganic chemical vapor deposition HfO2 films annealed in O2

Abstract

Composition, atomic transport, and chemical reaction were investigated following annealing in ${\mathrm{O}}_2$ of ultrathin ${\mathrm{HfO}}_2$ films deposited on Si substrates thermally nitrided in NO. The as-prepared thin film composition was established by Rutherford backscattering spectrometry, nuclear reaction analysis, and x-ray photoelectron spectroscopy as a ${\mathrm{HfO}}_2$ film on an intermediate layer containing silicon oxynitride, hafnium silicate, and possibly hafnium–silicon oxynitride. O penetration, incorporation in the bulk of the ${\mathrm{HfO}}_2/{\mathrm{SiO}}_x{\mathrm{N}}_y$ structure, and oxidation of the substrate forming ${\mathrm{SiO}}_2$ were observed.