Papers by Keyword: Equilibrium Vapor Pressure

Abstract: The numerical modeling of the SiC bulk growth process by physical vapor transport has been established as the essential tool for the process development, especially for understanding and predicting the favorable growth conditions. An accurate computation of mass transfers is strongly dependent on the equilibrium partial pressure calculations. In this paper, we compare the relative impact of the different thermodynamic databases available on the full PVT process modeling. We found that whatever the database used, the trends regarding growth rate calculation, crystal shape, Si/C ratio are correctly described and none of the database would bring about unacceptable errors from the process development point of view even if some discrepancies in the absolute values could be obtained.

Abstract: High temperature chemical vapor deposition (HTCVD) simulations of silicon carbide (SiC) were demonstrated with experimental results. A vertical cylindrical reactor was used in an RF inductive heating furnace and the temperature was more than 2200
. SiH4 and C3H8 were used as source gases and H2 as carrier gas. A gas phase reaction model from the literature was used on the condition that the gas phase reaction is a quasi-equilibrium state. It was found that the major species were Si, Si2C, SiC2 and C2H2 in the gas phase reaction model as well as in the thermodynamic equilibrium calculation. Sublimation etching was considered in the surface reaction rates by modifying partial pressures of species with equilibrium vapor pressures. CFD-ACE+ and MALT2 software packages were used in the present calculation. The sticking coefficients were determined by fitting the calculated growth rates to the experimental ones. The simulated growth rate in a different reactor is in good agreement with the experimental value, using the same sticking coefficients. The present simulation could be useful to design a new reactor and to find optimum conditions.