A KINETICS AND TRANSPORT MODEL OF DICHLOROSILANE CHEMICAL-VAPOR-DEPOSITION

Computational fluid dynamics is employed to examine silicon growth on a (100) surface in a dichlorosilane-hydrogen chemical vapor deposition (CVD) system. Species balances are solved in conjunction with mass, m omentum, and energy balances to predict growth rates in the system. Th e gas-phase mechanism includes the DCS decompositions SiH2Cl2 --> SiCl 2 + H-2 and SiH2Cl2 --> SiHCl + HCl and the surface mechanism accounts for adsorption and growth from SiCl2, SiHCl, and SiH2Cl2. Arrhenius p lots from the model show good agreement with experiment for overall gr owth rates at low DCS inflow concentrations but over predicts growth r ates for higher DCS inflow concentrations. A sensitivity analysis is p resented in the form of Arrhenius plots for several of the more import ant reactions included in the mechanism. The model suggests that growt h rates are very sensitive to the gas-phase decomposition of SiH2Cl2 a nd the dissociative adsorption of SiH2Cl2 and not very sensitive to th e dissociative adsorption of H-2 and the activation energy for the sur face growth from adsorbed SiCl and H by elimination of HCl.