AVS 59th Annual International Symposium and Exhibition
    Plasma Science and Technology Thursday Sessions
       Session PS-ThP

Paper PS-ThP19
The Role of Ions in the Gas-Surface Interactions of Nitrogen Oxide Plasma Systems

Thursday, November 1, 2012, 6:00 pm, Room Central Hall

Session: Plasma Science and Technology Poster Session
Presenter: J.M. Blechle, Colorado State University
Authors: J.M. Blechle, Colorado State University
M.F. Cuddy, Colorado State University
E.R. Fisher, Colorado State University
Correspondent: Click to Email
Improving upon the effectiveness of substrates that are used in vehicular emissions abatement hinges on the ability to elucidate the contributions of various gas-phase species in surface reactions. Utilizing inductively coupled plasmas, the role of ions on surface reactivity is investigated to improve and tailor surfaces for the reduction of nitrogen oxide (NxOy) species. Here, nascent ions are monitored via mass spectrometry and energy analysis for NO, N2O, NO2, and a 50/50 mixture of N2 and O2 precursor gases. The mean ion energy (<Ei>total) determined for all ions within each respective plasma system shows a strong positive correlation with applied rf power and a negative correlation with system pressure for all precursors studied. Ions also play varying roles in the surface scatter of NO radicals as demonstrated by the imaging of radicals interacting with surfaces (IRIS) technique. The net effect of ions on surface processing is dependent upon plasma parameters including the choice of precursor gas. Scatter coefficients (S), determined for ion-limited plasma systems are compared to ion-rich systems to correlate <Ei>total and scatter, which suggests a need for precise control of the chemistry occurring between the gas-phase and surface. Such information lends itself not only to the evaluation of plasma processing as a method of NxOy emission control, but also to improve current substrates and techniques.