Sihch+f: A potential reaction system for preparing uniform sic film predicted by using an ab initio molecular orbital method

Abstraction reactions and substitution reactions on SiHCH by an F atom were studied on the basis of an ab ini-tio molecular orbital method. The structures and the total energies of the reactants, the transition states, and the products were obtained at a third order M0ller Plesset (MP3)/D95**//Har-tree Fock (HF)/D95** and an MP3/6- 21+G//HF/6-21+G level. The activation energies for hydrogen abstractions from Si and C were –5.20 kcal/mol and 1.65 kcal/mol, respectively, while those for substitution reactions caused by Si attack and C attack were 20.96 kcal/mol and 25.58 kcal/mol, respectively. The activation energies for hydrogen abstraction reactions which retained an Si-C bond were much lower than those for substitution reactions by which an Si-C bond was cleaved. Thus, the SiHCH+F system was proven to be promising for preparing a uniform SiC film at relatively low temperatures. © 1994 IOP Publishing Ltd.