Metastable VO2 complexes in silicon: experimental and theoretical modeling studies

Abstract

We report on a combined experimental and theoretical study of the metastable form of the vacancy-dioxygen defect in Si labeled VO2*. Important new experimental observations are the 2 detection of mixed local vibrational modes of VO*(2) in O-16, O-18 co-doped samples, the determination of the position of LVM bands for the negatively charged defect, and an assignment of an acceptor level at about E-c - 0.05 eV. Defect energetics, electrical levels and LVM frequencies of the VO*(2) complex are also investigated by ab-initio density-functional modeling. We find it to be a bistable defect which accounts well for the experimental data. The metastable form produces an acceptor state at similar to 0.05 eV below E-c, and can be thought of as a VO defect perturbed by interstitial oxygen