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Reactive Atmospheric Plasma processIng - eDucation network

Final Report Summary - RAPID (Reactive Atmospheric Plasma processIng - eDucation network)

RAPID | Reactive Atmospheric Plasma processIng - eDucation network
Plasma processing of materials and surfaces is a key technology for many manufacturing steps in the high-end industries of Europe. The applications are numerous ranging from microelectronics to nanoelectronics, automotive, packaging up to the biomedical sector. The usage of non-equilibrium plasmas, which can be operated at atmospheric pressure were processed successfully in this project.
The successful creation of homogeneous stable non-equilibrium noble gas or nitrogen plasmas at atmospheric pressures is, however, only the first step. Even more challenging is the transfer of these plasmas into their reactive counterparts, namely introducing larger and more complex molecules such as silane for solar cell production, siloxanes for barrier coatings on polymers, or biomolecules for biomedical applications. Furthermore, the simulation of complex chemistry processes within the applied plasmas were developed and executed.

RAPID (Reactive Atmospheric Plasma processIng - eDucation network) was an interdisciplinary initial training network (ITN) at the intersection of chemistry, physics and engineering aimed particularly at the development of non-equilibrium reactive processes in atmospheric pressure plasmas. Emerging research topics and fields such as large area solar cells, barrier coatings to improve the permeation properties of polymers and plasma chemical gas conversion are selected within RAPID. The research success was based on a specific training consisting mainly of newly designed workshops covering diverse aspects such as modeling and simulation of plasmas and surfaces, diagnostics to feed these models and the implications for industrial scale-up and the realization of an interdisciplinary training involving the disciplines of physics, chemistry, and engineering. This research and training goals were accomplished in a coordinated effort involving 10 academic and 11 industrial partners from 8 European countries.

Full Partners: Ruhr-University Bochum, Germany | Eindhoven University of Technology, The Netherlands | University of Antwerp, Belgium | CNRS, France | FUJI, The Netherlands | University of Ulster, United Kingdom | University of Manchester, United Kingdom | VITO, Belgium | Tyndall National Institute, Ireland | Fraunhofer IST, Germany
Associated Partners: TNO, The Netherlands | SEMCO, France | CPI, France | Plasmawerk, Germany | BOSCH, Germany | Oxford Instruments, United Kingdom | Tantec, Denmark | InnoPhysics, The Netherlands | Plasma Clean Ltd, United Kingdom | Picosun Oy, Finland | DIFFER, The Netherlands

The realization of reactive atmospheric non-equilibrium processing plasmas was based on understanding the non-equilibrium chemistry in these plasmas and to control the flow of energy through the systems. This understanding was based on a careful diagnostic of the atmospheric pressure (AP) plasmas in combination with predictive modeling. In a next step, this was applied to different application cases ranging from plasma catalysis, thin film barriers and thin film electronics.

The diagnostic of AP plasmas was performed using diode laser infrared absorption spectroscopy and molecular beam mass spectroscopy. It is shown that internally excited species dominate the reaction chemistry. These are singlet oxygen molecules and oxygen atoms in noble gas plasmas containing oxygen, and excited water species in almost all AP plasmas, because water impurities are difficult to avoid in these systems. A dominant test case was also the plasma conversion of CO2 as a climate gas, where the reaction chemistry is changing in the effluent converting short living species such as O, vibrationally excited CO2 into long living radicals or stable species such as H2O2 or OH, or CO. The direct analysis of more reactive plasma from silicon precursors showed to be difficult, because the reactive species densities are very low, due to the high reaction rate at the confining surfaces.

The plasma chemistry has been successfully modelled using rate equation systems as well as ab-initio surface interaction modelling. Especially the benchmarking of these model by large data sets from diagnostics showed to be essential.

The application of AP plasmas was especially successful with the implementation of silicon oxide based barrier coatings on polymers, which yielded world record low values for water permeation. This is essential for OLEDs. In addition, the functionalization of polymer surfaces for plasma printing conducting layers and for the preparation of nanoparticles by AP plasma was successfully implemented.

Every fellow worked on her/his own project in close cooperation with other researchers. Our workshops, symposia and secondments were excellent opportunities to deepen the cooperation and foster exchange and know how transfer. All fellows interacted with the other full partners via secondments. This was especially helpful in the coordinated diagnostics campaigns and for the exchange in modelling capabilities. The exchange with industry partners was also successful in many cases, although the main implementation focus of some industry partners changed over the duration of the project. In those cases, the focus of the secondments had been adapted to emphasize more general aspects of an industrial workplace.

All ESR fellows will finish and defend their thesis project in fall of 2017 or in the beginning of 2018. All ERs found a permanent position in industry or academy during the project. The RAPID consortium has been completed in a final symposium in association whit the international workshop on microplasmas (IWM 9).

Contact Details:
RAPID Coordination | Office Ruhr-Universität Bochum | Faculty of Physics and Astronomy | NB 5/126 | 44780 Bochum | Germany
e-Mail: ; phone: +49 234 32 24576;