CHARACTERIZATION OF DEFECTS IN AMORPHOUS SIO2 IMPLANTED WITH OXYGEN IONS

Electron paramagnetic resonance (EPR) spectra of oxygen-implanted high-purity silica at temperatures ranging from 120 to 300 K have been measured at 9.7 GHz. Silica disks 2.0 cm in diameter and 0.1 cm thick were implanted with O+ ions at 140 keV with beam currents < 3-mu-A/cm2 and doses that ranged from 8 x 10(15) to 8 X 10(16) ions/cm2. Paramagnetic defects have been observed, two of which are similar to defects formed by gamma-ray irradiation of silica (E' center and the peroxy-radical (POR)). The POR shows several temperature-dependent features while the E' center has a dose-dependent annihilation cross section, as previously reported by Golanski, Devine, and Oberlin [J. Appl. Phys. 56 (1984) 1572]. Implantation of oxygen hinders defect formation of oxygen deficient defects such as the E' center while favoring production of oxygen-excessive defects such as the POR.