Characterization of a silicon carbide thin layer prepared by a self-propagating high temperature synthesis reaction

Abstract

Silicon carbide was deposited by a self-propagating high temperature synthesis reaction between graphite and silicon layers on an oxide substrate. Chemical analyses by Auger electron microscopy and X-ray diffractometry revealed that the final product was beta-SiC without an inter-diffusional layer at the interface between the carbide and graphite layers. Transmission electron microscope observation showed that the silicon carbide layer has fine crystalline structure. Numerical analysis showed that the combustion limit decreases with initial reaction temperature, which means that additional heat is required for the complete reaction. Activation energies between liquid silicon and carbon fiber or carbon black were 2875 and 1782 kJ/mol, respectively. The silicon carbide prepared by the combustion reaction between silicon and carbon was formed by the carbon diffusion at the interface between liquid silicon and silicon carbide. The reaction rate significantly depended on the specific surface area of carbon.