High‐temperature kinetics of some Si‐ and Cl‐containing ceramic precursors

Abstract

This article summarizes our recent experimental investigations of high-temperature kinetics of Si-and Cl-containing precursor molecules relevant to chemical vapor synthesis and ceramic processing. Reaction systems using SiCl 4 and SiHCl 3 highly diluted in argon, which were studied in a shock tube using the combination of thermal pyrolysis and laser flash photolysis methods, are described. In situ concentrations of the atomic species Si, Cl, and H were measured simultaneously using the atomic resonance absorption spectroscopy. The measured properties were sensitive to a limited number of elementary reactions, which could be analyzed in terms of rate coefficients.

Gas‐Phase and Surface Kinetics of Epitaxial Silicon Carbide Growth Involving Chlorine‐Containing Species

“…[26,27] As a preliminary result, the system was found particularly sensitive to gas-phase reactions G-139, G-144, and G-153 of the Supporting Information, reflecting previous thermochemical studies. [30][31][32] As final remark, two points can be made about the mechanism developed here with respect to particle formation and film etching. This mechanism is able to describe the growth of silicon carbide both in the presence and absence of chlorinated species.…”

“…[14,29] Here the attention was focused on the introduction of a set of reactions aimed at describing the profile concentrations along the reactor of the main chlorinated silicon species. [30][31][32] In particular, a few reactions between the most abundant silicon species (i.e., SiH 2 , SiH, and Si) and HCl were introduced in order to link the silane/propane to the trichlorosilane mechanism (i.e., reactions G-139, G-144, and G-153 of the Supporting Information). Schematically, the gas-phase mechanism can be divided into four different sections; ᭹ light hydrocarbons pyrolysis, ᭹ silane pyrolysis, ᭹ mixed organosilicon formation reactions, ᭹ HCl reactions with silicon fragments, as also highlighted in the Supporting Information.…”

Kinetics of halide chemical vapor deposition of silicon carbide film

“…The reaction mechanism documented by Danielsson et al [6] is regarded as reliable and is thus employed for calculating the carbon-side reactions in this study. Further, the thermal decomposition of SiCl 4 was investigated by Kunz and Roth [16], whose study, using thermal pyrolysis and laser flash photolysis methods in the temperature range of 1560-3570 K, suggests that SiCl 4 decomposes into SiCl m (m ¼ 0, 1, 2, 3) species at high temperatures through a simple mechanism including sequential abstraction of four Cl atoms. In this study, we employed this same reaction path excluding the dissociation of SiCl, as it is only observed to take place at temperatures beyond 2200 1C, which exceed the upper limit of growth temperature considered in this work.…”

The Predicted Heat of Formation of Several Si-Cl-O-H and Ti-Cl-O-H Species

“…Recently, Fourier transform infrared spectroscopy was used to observe TiO 2 formation in premixed flames of titanium tetraisopropoxide, methane, and oxygen. 1 Previous modeling studies have focused on the coagulation of the TiO 2 particles. 123 Teyssandier and Allendorf have previously modeled the Ti-Cl-H system by using Rice-Ramsberger-Kassel-Marcus to predict reaction rates.…”

“…123 Teyssandier and Allendorf have previously modeled the Ti-Cl-H system by using Rice-Ramsberger-Kassel-Marcus to predict reaction rates. 1 …”