Capturing Properties of Two-Fold Coordinated Nitrogen Atom in Silicon Oxynitride

Abstract

ABSTRACTElectronic structure of two-fold coordinated nitrogen atom ≡Si2N• in Si3N4 and SiOxNy is studied in different charged states by the semiempirical quantum-chemical method MINDO/3 taking into account an atomic relaxation. It is shown theoretically that the neutral paramagnetic defect ≡Si2N• captures an electron, therefore it is an electron trap in Si3N4 and SiOxNy. The calculations show that the capturing of hole by the ≡Si2N• defect can be energetically favorable only for large oxygen concentration in oxynitride. It is predicted that the electron localization by the ≡Si2N• defect will result in the ESR signal disappearance.