H/D isotope exchange reaction of SiH<sup>+</sup><sub>3</sub> with SiD<sub>4</sub> and SiD<sup>+</sup><sub>3</sub> with SiH<sub>4</sub>: Evidence for hydride stripping reaction
作者:W. D. Reents、M. L. Mandich
DOI:10.1063/1.458860
日期:1990.9
We have measured the reaction rates and product distributions for SiHxD+3−x reactions with SiH4 and SiD4. The measured reaction rates for SiH+3 and SiD4 (26.1±1.0×10−10 cc/molecule s) and for SiD+3 and SiH4 (23.1±1.0×10−10 cc/molecule s) are greater than the calculated Langevin collision rate (12.3–12.4×10−10 cc/molecule s). Also, the product distribution observed for H/D exchange is nonstatistical. Dual, competing reaction mechanisms are invoked to account for these observations: reaction via formation of an ion-molecule complex and reaction via long-range hydride stripping. Using an expected product distribution calculated from reaction thermochemistries, the relative contributions of the two mechanisms is obtained for each reaction examined. The reaction rate for the ion-molecule complex mechanism is calculated to be at the Langevin collision rate within experimental error. The reaction rate for the stripping mechanism varies from 1–4×10−10 cc/molecule s (10–30% of the Langevin collision rate) for the mixed isotope ions SiH2D+ and SiHD+2 to 12–18×10−10 cc/molecule s (100%–150% of the Langevin collision rate) for the isotopically pure ions SiH+3 and SiD+3. The faster than Langevin reaction rates lower the expected low field mobility of SiH+3 in silane plasmas by 70% to ∼340 cm2 Torr/V s.
Rotational structure of ΔνSi-H=7 and 8 overtone transitions of SiHD3
作者:A. Campargue、M. Chenevier、F. Stoeckel
DOI:10.1016/0301-0104(89)87109-5
日期:1989.10
Ground state rotational and K = 3 splitting parameters determined from high resolution infrared spectra: H28SiD3, H70GeD3 and H120SnD3
作者:Hans Bürger、Helmut Ruland、Luciano Fusina
DOI:10.1016/s0009-2614(97)00192-9
日期:1997.4
High-resolution (ca. 0.003 cm(-1)) FTIR spectra in the nu(5) range of HSiD3 and monoisotopic (HSnD3)-Sn-120 were recorded and analyzed to yield ground state parameters by means of combination differences. The splitting of the ground state K = 3 level into A(+) and A(-) sublevels was detected and could be equivalently accounted for by two different models. Model I involves Delta k = +/- 3 interactions which affect all K levels. The value of the interaction constant epsilon strongly depends on those of C-0 and D-K,D-0, and J-dependent distortion parameters different to those from model II are obtained. This involves Delta k = +/- 6 interactions which account almost exclusively for the K = 3 splitting in the HMD(3) molecules, M = Si, Ge and Sn. Also including data for (HGeD3)-Ge-70, obtained from a re-analysis of previous nu(4) and nu(5) spectra for the K = 3 transitions, the following values of the model II splitting parameter h(3) were obtained (all in 10(-11) cm(-1)): (HSiD3)-Si-28 3.996(14), (HGeD3)-Ge-70 4.058(49), (HSnD3)-Sn-120 3.637(33).