Thermodynamic analysis on deposition of SiBCN ceramic by low pressure chemical vapor deposition/infiltration from SiCH3Cl3BCl3NH3H2Ar system

In order to guide the kinetic deposition experiments of siliconboron carbonitride ceramics (SiBCN) from SiCl3CH3NH3BCl3H2Ar system, the thermodynamic calculation was undertaken using Factsage software. Predominant condensed phases at equilibrium were SiC, Si3N4, BN, B4C and C. The area of phase regions was affected by deposition parameters, such as temperature, total pressure, dilute H2 ratio, nCH3SiCl3/(nNH3 + nBCl3) and nNH3/(nNH3 + nBCl3). The results showed that SiBCN ceramics with desired phases, such as C + SiC + BN, could be obtained via this system by controlling above parameters theoretically. Kinetic verification at 900 °C demonstrated that SiBCN ceramic could be obtained by low pressure chemical vapor deposition/infiltration from this system. The deposition was amorphous from XRD spectra and mainly constituted by CC, SiN and SiC bonds from XPS analysis, which was in agreement with the results of thermodynamic calculation in general.