Thermodynamics, Kinetics, and Microstructure of SiC by Chemical Vapor Deposition from the MTS‑H₂ System

3C-SiC has desirable physical and chemical characteristics and has been used in semiconductor, aerospace, and other fields. However, the reaction mechanisms with methyltricholorosilane (CH₃SiCl₃, MTS) as the single-source precursor are still unclear due to the complexity of chemical reactions during the CVD process. In this work, the thermodynamic equilibrium, phase constituents, and microstructure of CVD-SiC were investigated on the MTS-H₂ system. The results showed that a relatively stoichiometric SiC coating can be obtained at temperatures above 1400 K, with relatively lower codeposited free carbon. Furthermore, the SiC exhibited a dense pyramidal microstructure along the (111) growth plane, with no apparent etching phenomena at 1543.15 K. Furthermore, three temperature regimes were identified, the M1 regime (1503.15 to 1543.15 K), the M2 regime (1543.15 to 1603.15 K), and the M3 regime (1603.15 to 1633.15 K), which correspond to chemical control, mass transfer, and thermodynamic control mechanisms, respectively. Further study of thermodynamic calculation results suggested that the abrupt decrease of reaction kinetics above 1603.15 K resulted from the drastic increase of the Cl radical and the removal of the Si atom to form the SiCl radical.