Theoretical study of the pyrolysis of methyltrichlorosilane in the gas phase. 2. Reaction paths and transition states.
The kinetics for the previously proposed 114-reaction mechanism for the chemical vapor deposition (CVD) process that leads from methyltrichlorosilane (MTS) to silicon carbide (SiC) are examined. Among the 114 reactions, 41 are predicted to proceed with no intervening barrier. For the remaining 73 reactions, transition states and their corresponding barrier heights have been explored using second-order perturbation theory (MP2) with the aug-cc-pVDZ basis set. Final energies for the reaction barriers were obtained using both MP2 with the aug-cc-pVTZ basis set and coupled cluster theory (CCSD(T)) with the aug-cc-pVDZ basis set. CCSD(T)/aug-cc-pVTZ energies were estimated by assuming additivity of basis set and correlation effects. Partition functions for the computation of thermodynamic properties of the transition states were calculated with MP2/aug-cc-pVDZ. Forward and reverse Gibbs free energy barriers were obtained at 11 temperatures ranging from 0 to 2000 K. Important reaction pathways are illustrated at 0 and 1400 K.
Ge
Yingbin
Y
Department of Chemistry, Iowa State University, Ames, Iowa 50011, USA.
Gordon
Mark S
MS
Battaglia
Francine
F
Fox
Rodney O
RO
D017554:Carbon Compounds, Inorganic / Q000737:chemistry; D004980:Ethane / Q000737:chemistry; D005030:Ethylenes / Q000737:chemistry; D006859:Hydrogen / Q000737:chemistry*; D007700:Kinetics; D008956:Models, Chemical; D044367:Phase Transition; D012821:Silanes / Q000737:chemistry*; D017655:Silicon Compounds / Q000737:chemistry; D013499:Surface Properties
D017554:Carbon Compounds, Inorganic; D005030:Ethylenes; D012821:Silanes; D017655:Silicon Compounds; D006859:Hydrogen; D004980:Ethane; C049552:methyltrichlorosilane; C022088:silicon carbide