| AVS 64th International Symposium & Exhibition | |
| Plasma Science and Technology Division | Wednesday Sessions |
| Session PS-WeA |
| Session: | Modeling of Plasmas |
| Presenter: | Andrew Gibson, University of York, UK |
| Authors: | A.R. Gibson, University of York, UK S. Schroeter, University of York, UK D. O'Connell, University of York, UK T. Gans, University of York, UK M.J. Kushner, University of Michigan J.-P. Booth, LPP-CNRS, Ecole Polytechnique, France |
| Correspondent: | Click to Email |
Low-temperature plasmas are widely used in a number of important applications. Specific examples include the etching of nanoscale structures in the semiconductor industry, electric propulsion of spacecraft, and as reactive species sources in biomedicine. In all of these applications, the plasma is bounded by surfaces and as a result, particle-surface interactions play a crucial role in defining its properties. These interactions act as sources and sinks of charged and neutral particles and enable energy transfer processes that heat and cool the plasma. As such, particle-surface interaction processes can influence all aspects of the plasma dynamics, and a proper understanding of their effects is crucial to optimizing a given application.
However, for a given plasma-surface combination a complete picture describing all possible particle-surface interaction processes is almost never known. This is a major reason why numerical simulations of low-temperature plasmas, where probabilities for various particle-surface interactions are used as boundary conditions, are often challenged to predict the results of experimental investigations. The work presented here seeks to provide insights into several key particle-surface interaction processes occurring in prominent applications of low-temperature plasmas using a combination of zero- and two-dimensional numerical simulations. In particular, the role of atomic neutral species surface recombination, excited species surface quenching, neutral thermal energy accommodation and electron- and ion-induced secondary electron emission probabilities in defining the properties of low-temperature plasmas will be discussed.
Examples of the importance of these particle-surface interactions in both low-pressure plasma sources, used in the semiconductor industry for etching processes, and atmospheric pressure micro-plasmas, used as radical sources in biomedicine, will be presented. It was found that surface processes play a key role in both examples and strongly affect plasma parameters important for applications. In the low-pressure case, this includes the neutral-to-ion flux ratio, a key parameter for precision etching processes. At atmospheric pressure, the densities of radical species and the overall chemical composition of the plasma, key parameters for interactions with biological tissue, are found to be particularly affected. In each example, areas where particle-surface interactions may be harnessed to optimize applications through the tailoring of surface properties will be highlighted.
Funding through the LABEX Plas@Par project, ANR-11-IDEX-0004-02 and UK EPSRC Manufacturing Grant (EP/K018388/1) is acknowledged