By using a first-principles approach, the electronic structure, defect structure and formation energy of native point defects in Y2O3 were studied. Vacancies, interstitials, and antisites in their relevant charge states were considered. It was found that, within the band gap of Y2O3, O vacancies, O interstitials, Y vacancies, and Y interstitials could be stable; depending upon the Fermi level and external chemical potentials. When the Fermi level was constrained to be within the band-gap of Si, O vacancies were the predominant defect type under low O chemical potential conditions. A higher O chemical potential led to O interstitials and ultimately to Y vacancies.

Native Point Defects in Yttria and Relevance to its Use as a High-Dielectric-Constant Gate Oxide Material - First-Principles Study. J.X.Zheng, G.Ceder, T.Maxisch, W.K.Chim, W.K.Choi: Physical Review B, 2006, 73[10], 104101 (7pp)