Thermodynamic analysis on deposition of Si-B-C-N ceramic by low pressure chemical vapor deposition/infiltration from SiCH3Cl3-BCl3-NH3-H-2-Ar system

摘要

In order to guide the kinetic deposition experiments of siliconboron carbonitride ceramics (Si-B-C-N) from SiCl3CH3-NH3-BCl3-H-2-Ar system, the thermodynamic calculation was undertaken using Fact sage 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 H-2 ratio, n(CH3SiCl3)/(n(NH3) + n(BCl3)) and nNH(3)/(n(NH3) + n(BCl3)). The results showed that Si-B-C-N ceramics with desired phases, such as C+SiC+BN, could be obtained via this system by controlling above parameters theoretically. Kinetic verification at 900 degrees C demonstrated that Si-B-C-N 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 C-C, Si-N and Si-C bonds from XPS analysis, which was in agreement with the results of thermodynamic calculation in general. (C) 2016 Elsevier Ltd. All rights reserved.