Defects in <i>a</i>-SiO2 deposited from a tetraethoxysilane-oxygen plasma

Abstract

We have studied intrinsic and extrinsic paramagnetic defects in as-deposited and annealed samples of amorphous SiO2 produced by plasma enhanced chemical vapor deposition using tetraethoxysilane and O2. In as-deposited samples the total paramagnetic defect density is 1.7×1018 cm−3 decreasing to 3× 1016 cm−3 after annealing for 10 min in N2 at 800 °C. We identify silicon dangling bond defects (O3 ≡Si•) and, tentatively, nonbridging oxygen-hole centers (O3 ≡SiO•), O−2 ions, C2H•5 radicals, and CO−2 radicals. We observe a defect having a g factor of 2.0040 which we cannot identify.