Untersuchung der Reaktionschemie von Silizium-haltigen Precursoren in einem Mikroplasmajet mittels Molekularstrahl-Massenspektrometrie

• Applicant: Professor Dr. Achim von Keudell
• Subject Area: Optics, Quantum Optics and Physics of Atoms, Molecules and Plasmas
• Term: from 2008 to 2012
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 50561352

• Final Report Year: 2011

Final Report Abstract

Reactive species are generated in reactive microplasma jets in the plasma bulk and are transported to the surface by the effluent. Thereby, surface modification or film deposition applications can be realized. This transport also implies a transfer of energy via dissociative recombination, Penning-ionization or -dissociation. By using molecular beam mass spectrometry employing a special sampling unit for atmospheric pressures, a unique instrument has been developed to analyze various microplasmas quantitatively. Thereby, the He/O2 mixtures and Ar/He/HMDSO mixtures have been analyzed. The production of reactive oxygen species (ROS) in He/O2 microplasma jets is measured and in agreement with corresponding TALIF measurement of a neighboring group. The production of O and ozone and metastable species has been modelled in agreement with the data. The dissociation pathway of HMDSO in microplasma jets has been quantified. It shows, that the HMDSO molecule preferably breaks at the Si-O bond, despite this bond is much stronger than the C-H bonds in the molecule. The resulting fragment may be the dominant growth precursor. The excess carbon is removed mainly by surface reactions with metastables incident from the plasma.

Publications

• A molecular beam mass spectrometer for radical detection at atmospheric pressures: the rotating skimmer concept, Review of Scientific Instruments 80, 055107 (2009)
  J. Benedikt, D. Ellerweg, A. von Keudell
  
• Characterization of the effluent of a He/O2 microscale atmospheric pressure plasma jet by quantitative molecular beam mass spectrometry, New Journal of Physics 12, 013021 (2010)
  D. Ellerweg, J. Benedikt, A. von Keudell, N. Knake, V. Schulz-von der Gathen
  
• , The mystery of O and O3 production in the ffluent of a He/O2 atmospheric pressure microplasma jet, (2011)
  D. Ellerweg, A. von Keudell, and J. Benedikt
  
• Deposition of SiOx films by means of atmospheric pressure microplasma jets, Proceedings of SAPP XVIII (2011)
  Jan Benedikt, Rüdiger Reuter, Dirk Ellerweg, Katja Rügner, Achim von Keudell
  
• Diagnostics of low and atmospheric pressure plasma by means of mass spectrometry, Proceedings of the SVC 2011
  J. Benedikt, D. Ellerweg, A. von Keudell
  
• Reaction chemistry in oxygen or hexamethyldisiloxane containing noble gas microplasma jets: a quantitative molecular beam mass spectrometry study, PhD thesis, Bochum 2011
  D. Ellerweg