ELECTRON-SPIN-RESONANCE STUDY OF RADIATION-INDUCED POINT-DEFECTS IN NITRIDED AND REOXIDIZED NITRIDED OXIDES

X-ray irradiated oxide, nitrided oxide, and reoxidized nitrided oxide films were studied with electron spin resonance. Nitridation of oxide films reduces the density of radiation-induced E' centers and creates bridging nitrogen center precursors, while reoxidation of nitrided oxides increases the number of radiation-induced E' centers, reduces the number of bridging nitrogen center precursors, and introduces overcoordinated nitrogen center-precursors. Nitridation and reoxidation of these films also changes the distribution of the radiation-induced defects. Our evidence supports earlier findings that the bridging nitrogen defect plays an important role in electron trapping in nitrided oxides and that the dominant hole trap in reoxidized nitrided oxides is not the E' center. Exposure to molecular hydrogen at room temperature annihilates paramagnetism of the nitrogen-associated centers and reduces that of the E' centers.