THEORETICAL-STUDY OF THE THERMOCHEMISTRY OF MOLECULES IN THE SI-C-CL-H SYSTEM

Ab initio electronic structure calculations coupled with empirical corrections are used to obtain a self-consistent set of heats of formation for molecules in the series CH(n)SiCl(m) (n, m = 0-3) and for selected molecules in the series (CH3)(n)SiH(m)Cl(p). Heats of formation are also reported for the series Cl(n)SiSiCl(m) (m, n = 0-3) and for HC=CSiCl2H and H2C=CH(SiCl2H). Gibbs free energies as a function of temperature and standard entropies are given for all molecules in the study. Heats of formation are used to evaluate potential pathways for the decomposition Of Cl3SiCH3, a common silicon carbide chemical vapor deposition precursor. The analysis includes the calculation of the transition state for the 1,2-elimination of HCl from Cl3SiCH3.