X-ray photoelectron spectroscopy analysis of zirconium nitride-like films prepared on Si(100) substrates by ion beam assisted deposition

Thin zirconium nitride films were prepared on Si(100) substrates at room temperature by ion beam assisted deposition with a 2 keV nitrogen ion beam. Arrival rate ratios ARR(N/Zr) used were 0.19, 0.39, 0.92, and 1.86. The chemical composition and bonding structure of the films were analyzed with X-ray photoelectron spectroscopy (XPS). Deconvolution results for Zr 3d, Zr 3p_3/2, N 1s, O 1s, and C 1s XPS spectra indicated self-consistently the presence of metal Zr⁰, nitride ZrN, oxide ZrO₂, oxynitride Zr₂N₂O, and carbide ZrC phases, and the amounts of these compounds were influenced by ARR(N/Zr). The chemical composition ratio N/Zr in the film increased with increasing ARR(N/Zr) until ARR(N/Zr) reached 0.92, reflecting the high reactivity of nitrogen in the ion beam, and stayed almost constant for ARR(N/Zr) ≥ 1, the excess nitrogen being rejected from the growing film. A considerable incorporation of contaminant oxygen and carbon into the depositing film was attributed to the getter effect of zirconium.