Laser-Excited Fluorescence Detection of Si₂ During Silane CVD

Abstract

Using laser-excited fluorescence, Si 2 has been observed in a CVD cell during the deposition of silicon from silane. The formation of Si 2 was predicted by our numerical model for CVD which includes a detailed treatment of the chemical kinetics and fluid flow in the gas phase. Our observations of Si 2 provide strong support for this model. We also find excellent agreement between the temperature dependence of silicon deposition rates predicted by the model and experimental deposition rates from the literature. These observations indicate that gas-phase chemical reaction kinetics are more important in silane CVD than has been recognized previously.