Gas-phase kinetics analysis and reduction of large reaction mechanisms exemplified in the case of SiC deposition

Chemical vapor deposition (CVD) is commonly used to grow epitaxial SiC layers at relatively high temperature from SiH4-C3H8-H-2 mixtures. In order to model the deposition process, the kinetics of the gas-phase reactions involved must be known accurately and the main reaction pathways must be identified. For this purpose, we have selected the most recent sets of reactions and related kinetic data available for the C-H and Si-H chemical systems. However, the full mechanism so obtained is too large to be included in a CVD reactor model, because of the computational time required for the calculations and numerical convergence problems. As a consequence, the full mechanism has been reduced using the so-called 'redundant species and reactions' method due to Turanyi. Since reactions between Si-H species and C-H species have not been considered, the C-H and Si-H mechanisms have been reduced separately. As a result, a smaller subset of reactions and species describing accurately the gas-phase reactivity in the Si-C-H system has been obtained. (C) 2003 Elsevier Science B.V. All rights reserved.