Ab initio and kinetic calculations for the reactions of Cl with SiHnCl4−n (n=1,2,3,4)

Abstract

The direct hydrogen abstraction reactions of Cl atom with SiH(n)Cl(4-n) (n=1,2,3,4) have been studied systematically using ab initio molecular orbital theory. Geometries have been optimized at the MP2 level with 6-311+G(d) basis set, QCISD(T)/6-311+G(d,p) has been used in the final single point energy calculation. The kinetic calculations of these reactions have been explored using the canonical variational transition (CVT) state theory method with small-curvature tunneling (SCT) effect correction over the temperature range of 200-2000 K. The CVT/SCT rate constants exhibit typical non-Arrhenius behavior and three-parameter rate-temperature formulas have been fitted for the reactions of Cl with SiH4, SiH3Cl, SiH2Cl2, and SiHCl3, respectively (in unit of cm(3) molecule(-1) s(-1)). The calculated CVT/SCT rate constants are in agreement with the available experimental values.

Crossed molecular beam ion-imaging study of the Cl + SiH4→ HCl + SiH3 reaction: product vibrational state-to-state correlation

“…In comparison with the SiH 3 REMPI spectrum from the F + SiH 4 -SiH 3 + HF reaction at 8.7 kcal mol À1 (Fig. 2(b)), 15 the REMPI spectrum for the SiH 3 radical from the Cl reaction with silane is very similar, except that v 2 = 5 peak is missing in the Cl reaction. The relative populations of SiH 3 in different vibration states are different between the two reactions.…”

“…The collision energy used in this experiment is well above the barrier of 2.5 kcal mol À1 derived by Pei and Li. 15 The SiH 3 product from the crossed beam reaction was detected using a one-color, (2 + 1) REMPI scheme via the E ˜2A 2 00 (4p) Rydberg state. 22 The REMPI laser beam from 410 to 420 nm was generated by a YAG (532 nm) pumped dye laser.…”

“…13 Ding and Marshall measured the rate constant of this reaction between 295 and 472 K. 14 In 2004, Pei and Li carried out a combined ab initio and kinetic study on this reaction, and the rate constants of this reaction between 200 and 2000 K were determined. 15 They have derived a reaction barrier to be 2.5 kcal mol À1 for this reaction. However, the dynamics of this reaction has not been studied in detail.…”

Kinetics of the Conversion of Silicon Tetrachloride into Trichlorosilane Obtained through the Temperature Control along a Plug-Flow Reactor

“…The remaining reactions, (R45)–(R63), adopted from , are also related to thermal decomposition of silane, chlorosilane, dichlorosilane, trichlorosilane, and hydrogen and are not provided in the other two sources mentioned above. These additional reactions may not play important roles under all conditions but were included to guarantee that any potentially important reaction is included and to build a model that can be applied in a wide range of conditions.…”

Pressure Dependence of Rate Coefficients for Formation and Dissociation of Pentachlorodisilane and Related Chemical Activation Reactions

“…For realizing faster and cheaper production of high‐quality solar‐grade silicon, the chemical reactions taking place both at the gas phase and at the surface need first to be understood in detail. Much effort has been devoted for elucidating the reaction mechanisms involved in the gas phase of silicon CVD processes, and the rate coefficients of many elementary reactions have been made available ; recently, we compiled a reaction model comprising 63 elementary steps based on a survey of the literature, and the model was able to predict the variation of species concentrations along a plug‐flow reactor designed to convert silicon tetrachloride into trichlorosilane, and predicted conversion efficiencies that agreed well with experimental results . However, all rate coefficients for the numerous unimolecular reactions included in the model were for the high‐pressure limit case, because too few sources of pressure‐dependent rate coefficients were available.…”