Paramagnetic defects in silicon carbide grains embedded in SiO2 matrix

Abstract

Paramagnetic defects in silicon carbide (SiC) grains embedded in SiO 2 thin films have been studied using electron paramagnetic resonance (EPR). The films prepared by co-sputtering of SiO 2 , Si and C targets followed by thermal annealing shows an infrared (IR) absorption peak of Si-C bonds at 800 cm -1 . In the sample annealed at 600°C, C dangling bond (DB) defects in SiC and defects in SiO 2 can be detected by X-band EPR spectra. The signal of the defects in SiO 2 disappeared and only the carbon DB was observed after thermal annealing at 1000°C. In the Q-band EPR spectra, carbon DB (g = 2.0026), silicon DB (g = 2.005) and the defects in SiO 2 were observed separately. The paramagnetic species show different dependencies on annealing temperature.