SIH3CH3+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 SiH3CH3 by an F atom were studied on the basis of an ab initio molecular orbital method. The structures and the total energies of the reactants, the transition states, and the products were obtained at a third order Moller 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 SiH3CH3+F system was proven to be promising for preparing a uniform SiC film at relatively low temperatures.