Nitrogen doping of SiC thin films deposited by RF magnetron sputtering
Silicon carbide thin films (Si x C y ) were deposited in a RF (13.56 MHz) magnetron sputtering system using a sintered SiC target (99.5% purity). In situ doping was achieved by introducing nitrogen into the electric discharge during the growth process of the films. The N 2 /Ar flow ratio was adjusted by varying the N 2 flow rate and maintaining constant the Ar flow rate. The structure, composition and bonds formed in the nitrogen-doped Si x C y thin films were investigated by X-ray diffraction (XRD), Rutherford backscattering spectroscopy (RBS), Raman spectroscopy and Fourier transform infrared spectrometry (FTIR) techniques. RBS results indicate that the carbon content in the film decreases as the N 2 /Ar flow ratio increases. Raman spectra clearly reveal that the deposited nitrogen-doped SiC films are amorphous and exhibited C–C bonds corresponding to D and G bands. After thermal annealing, the films present structural modifications that were identified by XRD, Raman and FTIR analyses.