First observation of the 29Si hyperfine spectra of silicon dangling bond centers in silicon nitride

We report the first observation of 29Si hyperfine spectra of the deep trapping center which dominates the electronic properties of silicon nitride films. Our results provide the first conclusive evidence that the center is a silicon ‘‘dangling bond’’ defect. Our results also demonstrate that the unpaired electron is highly localized (about 75%) on the central silicon and that the wave function is primarily p type.