From monosilane to crystalline silicon, Part II: Kinetic considerations on thermal decomposition of pressurized monosilane

Kinetic aspects of the thermal decomposition of monosilane at 690–830 K and initial pressures of 0.1–3.7 MPa in a free-space reactor are considered. Neglecting the preparatory initiation period for the reaction (which is difficult to evaluate under the present dynamic conditions), the onset temperature for the decomposition is stipulated to some 700–710 K, independent of the initial monosilane pressure. The overall reaction appears to be of first order throughout the progressing decomposition process. We observe considerably lower reaction rates under the high-pressure conditions than existing models in the literature suggest. A modified model is proposed that simulates the observed reaction rates within ±1% and moreover predicts credible concentrations of the involved gaseous species. A key feature of the modified model is incorporation of two third-body assisted surface reactions, which generate monosilane from disilane and disilane from trisilane. © 2006 Wiley Periodicals, Inc. Int J Chem Kinet 38: 309–321, 2006