主题：【求助】Thermal Decomposition Mechanism of Disilane

Kazumasa Yoshida, Keiji Matsumoto,Tatsuo Oguchi,
Kenichi Tonokura,*§ and Mitsuo Koshi

Department of Chemical System Engineering, School of
Engineering, The University of Tokyo, 7-3-1 Hongo,
Bunkyo-ku, Tokyo 113-8656, Japan, and Department of
Ecological Engineering, Toyohashi University of
Technology, Toyohashi 441-8580, Japan
J. Phys. Chem. A, 2006, 110 (14), pp 4726–4731
DOI: 10.1021/jp055280p

Publication Date (Web): March 18, 2006
Copyright © 2006 American Chemical Society

Abstract
Thermal decomposition of disilane was investigated using time-of-flight (TOF) mass
spectrometry coupled with vacuum ultraviolet single-photon ionization (VUV-SPI) at a
temperature range of 675−740 K and total pressure of 20−40 Torr. SinHm species were
photoionized by VUV radiation at 10.5 eV (118 nm). Concentrations of disilane and trisilane
during thermal decomposition of disilane were quantitatively measured using the VUV-SPI
method. Formation of Si2H4 species was also examined. On the basis of pressure-dependent
rate constants of disilane dissociation reported by Matsumoto et al. [J. Phys. Chem. A 2005,
109, 4911], kinetic simulation including gas-phase and surface reactions was performed to
analyze thermal decomposition mechanisms of disilane. The branching ratio for (R1) Si2H6 →
SiH4 + SiH2/(R2) Si2H6 → H2 + H3SiSiH was derived by the pressure-dependent rate constants.
Temperature and reaction time dependences of disilane loss and formation of trisilane were
well represented by the kinetic simulation. Comparison between the experimental results and
the kinetic simulation results suggested that about 70% of consumed disilane was converted to
trisilane, which was observed as one of the main reaction products under the present
experimental conditions.