Ab initio Chemical Kinetic Studies for Reactions of H-atoms with Silicon Hydrides (SinH2n+2, n=1~2) and Decomposition Reactions of Silicon Hydride Radicals (SinH2n+1, n=1~3)

• Main Authors: Wu, Shang-Ying, 吳尚穎
• Other Authors: Wu, Jong-Shinn
• Format: Others
• Language: en_US
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/66016085146857006748

碩士 === 國立交通大學 === 機械工程學系 === 98 === The reactions of hydrogen atoms with silicon hydrides (SinH2n+2, n=1~2) and the decomposition reactions of silicon hydride radicals (SinH2n+1, n=1~3) are relevant to the understanding of catalytic chemical vapor deposition (Cat-CVD) and plasma enhanced chemical vapor deposition (PECVD) processes. In the present proposed study, these reactions are investigated by means of ab initio molecular-orbital and chemical kinetics theoretical calculations. In the first phase of the study, we validate the calculated enthalpies of the reaction by considering further isodesmic reactions, such as SiH+CH4→SiH4+CH, SiH3+CH4→SiH4+CH3, Si2H5+C2H6→Si2H6+C2H5 and so forth; additionally, the predicted enthalpies of the formation for essential compounds are compared with the available experimental data. Finally, transition state theory (TST) with unsymmetrical Eckart potential energy barriers is employed to obtain the rate coefficients of the hydrogen abstraction reaction. Rate coefficients relevant to the thermal decomposition reaction of silicon hydride radicals are calculated by employing canonical variational transition state theory (CVTST), the Rice-Ramsperger-Kassel-Marcus (RRKM) theory with master equation or variational transition-state theory (VTST). These rate coefficients are not only predicted in the practical ranges of temperature and pressure but are also compared with the available experimental results wherever possible.