We report the first observation of a nitrogen dangling bond center in nitrided thermally grown silicon dioxide films on silicon. Interpretation of the 14N hyperfine parameters indicates that the unpaired electron wave function is strongly localized on the central nitrogen and that the wave function is highly p in character.

Radiation-induced hole trapping in reoxidized nitrided silicon dioxide (RNO) was studied with electron spin resonance spectroscopy. It is demonstrated that the dominant hole trap in RNO is not the well known E′ center of conventional oxides. This finding confirms our earlier speculation, based on detrapping experiments, that the dominant hole trap in RNO is a species distinctly different from that in conventional oxide.