Raman microscopy study of pulsed laser ablation deposited silicon carbide films

Silicon carbide films have been deposited by pulsed laser ablation. The sample microstructure was studied by means of SEM imaging and spatially resolved Raman spectroscopy. Some inhomogeneities, on an otherwise structureless sample surfaces, were evident in the SEM images. A detailed Raman imaging study was carried out over a properly selected area including some inhomogeneous spots. Analysis of the spectral features relative to phonon modes revealed a variety of structural configurations. In the homogeneous region, the amorphous phases of silicon carbide, graphitic carbon and silicon were identified. On the other hand the inhomogeneous spots contained predominantly microcrystalline phases of both silicon and graphitic and/or tetrahedral carbon species. Micro-Raman spectroscopy provided an excellent tool, in giving local structural information by selectively probing a microscopic scattering volume.