Thermodynamics for the Chemical Vapor Deposition of SiCl₄-TiCl₄-CCl₄-H₂ System

The thermodynamic calculations and the experimental results for the chemical vapor deposition of the Si-Ti-C-H-Cl system using SiCl₄, TiCl₄, CCl₄ and H₂ as source gases were compared. The thermodynamic calculations well explained the experimental results for the formation of such phases as the SiC+TiC, the SiC+TiC+C and the TiC+Ti₃SiC₂. The main gas species in equilibrium are (H₂), (HCl), (SiCl₂) and (TiCl₈). The equilibrium (H₂) and (HCl) partial pressures are almost independent of temperature. The equilibrium (SiCl₂) partial pressure increases with increasing temperature, and the equilibrium (TiCl₈) partial pressure decreases with increasing temperature. The theoretical deposition efficiency of <SiC> decreases with increasing temperature, and that of <TiC> increases with increasing temperature. The calculated compositions of SiC/(SiC+TiC) in the SiC+TiC phase were almost in agreement with the experimental values. The calculated compositions of SiC/ (SiC+TiC) decrease with increasing temperature. However the experimentally obtained compositions increased with increasing temperature, which may be caused by the kinetic restriction for the formation of the <SiC> at lower deposition temperatures.