Mutual deactivation of electrically active F interstitials and O vacancies into fluorine-oxygen-vacancy complexes in SiO 2

摘要: Based on first-principles density-functional calculations, we show that F interstitials in ${\text{SiO}}_{2}$ behave as negative fixed charges or charge traps, depending their positions relative to the $\text{Si}/{\text{SiO}}_{2}$ interface. By contrast, they deactivate O vacancies, which are dominant traps ${\text{SiO}}_{2}$, by forming F-pair complexes at sites, while a defect complex of an vacancy and atom is still electrically active negative-U center. Our model successfully explains controversial points earlier experimental analyses suggests proper thermal annealing process under moderate doping level will lead improved electrical properties for effectively deactivating vacancies into complexes.