Radiation-Induced Defect Centers in Thermally Grown Oxide Films

Electron spin resonance and etch-back techniques have been employed to identify radiation-induced defect centers in thermally grown oxide films on SOS wafers and to determine their spatial distribution in the oxide film. The only defect identified was the E´ center, which was found to be indistinguishable from E´ centers in irradiated bulk fused silica samples. The distribution of E´ centers in-oxide films irradiated to a dose of 108 rad (Si) was observed to consist of a uniform bulk distribution plus a concentration build-up near the Si-SiO2 interface. The application of a positive 10 volt bias to a 1.08kÃ… gate oxide during gamma irradiation produced an order of magnitude increase in the E´ center concentration.