Paramagnetic defects in silicon carbide grains embedded in SiO2 matrix

Paramagnetic defects in silicon carbide (SiC) grains embedded in SiO2 thin films have been studied using electron paramagnetic resonance (EPR). The fi lms prepared by co-sputtering of SiO2, 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 degreesC, C dangling bond (DB) defects in SiC and defects in SiO2 can be detected by X-band EPR spectra. The signal of the defects in SiO2 disappeared and only the carbon DB was observed afte r thermal annealing at 1000 degreesC. In the Q-band EPR spectra, carbon DB (g = 2.0026), silicon DB (g = 2.005) and the defects in SiO2 were observed separately. The paramagnetic species show different dependencies on anneali ng temperature. (C) 2001 Elsevier Science B.V. All rights reserved.