Micro-Raman study of reactive pulsed laser ablation deposited silicon carbon alloy films

Si1-xCx:H alloy thin films were deposited by pulsed laser ablation of a crystalline silicon target in a reactive environment. The microstructure of the films was studied by means of scanning electron microscopy (SEM) images and spatially resolved Raman spectroscopy. The films were found to consist of mixed microcrystalline and amorphous phases, with a silicon crystallite size of 5-6 nm. Incorporation of carbon and hydrogen was found to occur mainly in the amorphous phase. Results showed that films growth is given by deposition of atomic and molecular sized material reacting with ionized species. Some inhomogeneities observed in the SEM images were attributed to rapid cooling of liquid droplets ejected from the target.