A Density Functional Theory Study of Chlorosilanes Polymerization in Silicon Epitaxy

The decomposition kinetics of chlorosilanes have been so far investigated up to the lower molecular weight fragments, not regarding the generation of telomeres. In this work Quantum Chemistry was employed to investigate gas phase polymerization of chlorosilanes in operating conditions proper to silicon epitaxy. Thermodynamic and kinetic parameters, molecular structures and transition state geometries were determined with Density Functional Theory (DFT), resulting in a series of fast condensation-reactions bringing to the production of telomeres. In particular, a large number of linear, branched and cyclic silicon- compounds were analyzed (up to Si6Clx species). Finally the kinetic scheme was embedded in a reactor simulation code, where significant amounts of such species were obtained.