Mechanisms and kinetics of the thermal decompositions of trichlorosilane, dichlorosilane, and monochlorosilane

✍ Scribed by K. L. Walker; R. E. Jardine; M. A. Ring; H. E. O'Neal

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 295 KB
• Volume: 30
• Category: Article
• ISSN: 0538-8066
• DOI: 10.1002/(sici)1097-4601(1998)30:1<69::aid-kin9>3.0.co;2-s

✦ Synopsis

Decomposition studies of trichlorosilane, dichlorosilane, and monochlorosilane at and respectively, are reported. The studies were made at fixed reactant 921 K, 872 K, 806 K, pressures over a range of total pressures in a wall conditioned, quartz reactor connected to a quadrupole mass-spectrometer. Products were monitored sequentially and continuously in time. The dichlorosilane decomposition was also studied by the comparative-rate single-pulse shock-tube method at temperatures around Two mechanisms of decomposition are 1250 K. considered: a silylene based mechanism initiated by molecular elimination reactions (Scheme I), and a free radical based mechanism initiated by bond fission reactions (Scheme V). Modeling tests of these mechanisms show that only the former is consistent with the experimental data. The decompositions are shown to be essentially nonchain processes initiated by the following pressure dependent reactions: HSiCl 94: SiCl ϩ HCl, H SiCl 91:

and High pressure Arrhenius parameters recommended for these H SiCl 95: HSiCl ϩ H .