Thermochemical stability of silicon-oxygen-carbon alloy thin films: A model system for chemical and structural relaxation at SiC-SiO2 interfaces

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 f unction of rapid thermal annealing between: 600 and 1100 degrees C using a combination of Fourier transform infrared spectroscopy, Raman scattering an d high-resolution transmission electron microscopy. Results showed that thr ee structural/chemical transformations took place upon annealing. The initi al reaction (600-800 degrees C) involved the loss of hydrogen bonded to bot h silicon and carbon. At intermediate temperatures (900-1000 degrees C) Si- O-C type bond was observed to form, and subsequently disappear after anneal ing to 1050 degrees C; The formation of ordered amorphous-SiC regions, nano crystalhne-Si regions, and stoichiometric, thermally relaxed SiO2 accompani ed the, disappearance of the Si-O-C bond at the 1050 degrees C annealing te mperature. Using this alloy as a model system, important information is obt ained for optimized processing of SiC-SiO2 interfaces;for device applicatio ns. (C) 1999 American Vacuum Society. [S0734-2101(99)16104-9].