Alloy thin films of hydrogenated silicon-oxygen-carbon (Si,C)O-x x<2, were deposited and. analyzed in terms-of changes in structure and bonding as a function of rapid thermal annealing between: 600 and 1100 degrees C using a combination of Fourier transform infrared spectroscopy, Raman scattering and high-resolution transmission electron microscopy. Results showed that three structural/chemical transformations took place upon annealing. The initial reaction (600-800 degrees C) involved the loss of hydrogen bonded to both silicon and carbon. At intermediate temperatures (900-1000 degrees C) Si-O-C type bond was observed to form, and subsequently disappear after annealing to 1050 degrees C; The formation of ordered amorphous-SiC regions, nanocrystalhne-Si regions, and stoichiometric, thermally relaxed SiO2 accompanied the, disappearance of the Si-O-C bond at the 1050 degrees C annealing temperature. Using this alloy as a model system, important information is obtained for optimized processing of SiC-SiO2 interfaces;for device applications.