Effects of O3 and H2O oxidants on C and N-related impurities in atomic-layer-deposited La2O3 films observed by in situ x-ray photoelectron spectroscopy

The effect of H2O and O3 oxidants on the behavior of residual C and N-related impurities as well as Si out-diffusion and interfacial layer formation in atomic-layer-deposited La2O3 films grown at 250 deg. C were examined using in situ x-ray photoelectron spectroscopy. The silicate formation was suppressed in a La2O3 film grown using O3 compared to that deposited using H2O, but interfacial layer growth was enhanced. The accumulation of C and N-related residues with low binding energy, which originated from incomplete reactions, was suppressed in La2O3 films grown using O3. However, the use of O3 resulted in La-carbonate phase in film.