Quantitative Analysis of Oxygen Deficiency in Epitaxial CeO2 Layers on Si by Detecting 18O Added for Stoichiometry

Oxygen deficiency in epitaxially grown CeO 2 layers on Si substrates by ultrahigh-vacuum evaporation is studied using secondary ion mass spectrometry (SIMS). 18 O 2 gas is externally introduced in the evaporation process for compensation of oxygen deficiency of the CeO 2 layer. Oxygen components in CeO 2 layers are analyzed, separately detecting secondary ions of Cs 16 O + and Cs 18 O + . The extrinsic oxygen content needed to obtain stoichiometric CeO 2 is determined to be in the range of 11–18%. These SIMS data agree well with the oxygen deficiency of ∼18% determined by Rutherford backscattering analysis of a nonstoichiometric CeO 2 layer grown without oxygen gas introduction.