The equilibrium state in the Si-O-C ternary system during SiC growth by chemical substitution of atoms

Abstract

The equilibrium state in the silicon-carbon-oxygen (Si-O-C) ternary system has been calculated in the framework of the thermodynamics of chemical reactions. It is established that, in the practically important temperature interval of 1000°C < T < 1400°C, the system initially consisting of crystalline Si and gaseous CO tends toward an equilibrium state comprising a mixture of four solid phases (Si, C, SiC, and SiO₂) and vapor mixture (predominantly of SiO, CO, Si, and CO₂). Equilibrium partial pressures of all gases in the mixture have been calculated. An optimum regime of SiC film growth from Si by the method of atomic substitution is proposed, whereby only SiC phase is growing while SiO₂ and C phases are not formed.