Synchrotron-based vacuum ultraviolet photolysis of supersonic free jets of SiH4

Paul Fons, Teruaki Motooka, Koichi Awazu, Hideo Onuki

Research output: Contribution to journalArticlepeer-review


We have measured the relative abundance of neutral photofragments in pulsed supersonic free jets of SiH4 excited in the wavelength range 115 to 170 nm using synchrotron radiation and quadrupole mass spectrometry (QMS). Using a sub-ionization QMS threshold electron-impact energy of 11 V and taking the difference between VUV irradiated and non-irradiated SiH4 jet pulses, the relative abundance of the neutral species Si, SiH, SiH2 and SiH3 was determined. The neutral Si signal exhibited a threshold wavelength of approx. 135 nm, reaching its maximum value at approx. 115 nm, the short wavelength limit of the current measurements. The SiH signal rose rapidly to a peak at approx. 158 nm, falling off rapidly to approx. 145 nm. An additional shoulder on the SiH signal was observed at approx. 138 nm that gradually diminished for λ < 125 nm. The SiH2 and SiH3 radicals exhibited a maximum near 145 nm with the SiH2 peak exhibiting a secondary maximum at approx. 128 nm.

Original languageEnglish
Pages (from-to)13-17
Number of pages5
JournalDenshi Gijutsu Sogo Kenkyusho Iho/Bulletin of the Electrotechnical Laboratory
Issue number1
Publication statusPublished - 1995 Jan 1
Externally publishedYes

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Electrical and Electronic Engineering


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