Industrial plasmas in academia

Abstract

The present review, written at the occasion of the 2014 EPS Innovation award, will give a short overview of the research and development of industrial plasmas within the last 30 years and will also provide a first glimpse into future developments of this important topic of plasma physics and plasma chemistry. In the present contribution, some of the industrial plasmas studied at the CRPP/EPFL at Lausanne are highlighted and their influence on modern plasma physics and also discharge physics is discussed. One of the most important problems is the treatment of large surfaces, such as that used in solar cells, but also in more daily applications, such as the packaging industry. In this contribution, the advantages and disadvantages of some of the most prominent plasmas such as capacitively-and inductively-coupled plasmas are discussed. Electromagnetic problems due to the related radio frequency and its consequences on the plasma reactor performance, and also dust formation due to chemical reactions in plasma, are highlighted. Arcing and parasitic discharges occurring in plasma reactors can lead to plasma reactor damages. Some specific problems, such as the gas supply of a large area reactor, are discussed in more detail. Other topics of interest have been dc discharges such as those used in plasma spraying where thermal plasmas are applied for advanced material processing. Modern plasma diagnostics make it possible to investigate sparks in electrical discharge machining, which surprisingly show properties of weakly-coupled plasmas. Nanosecond dielectric barrier discharge plasmas have been applied to more speculative topics such as applications in aerodynamics and will surely be important in the future for ignition and combustion.Most of the commonly-used plasma sources have been shown to be limited in their performance. Therefore new, more effective plasma sources are urgently required. With the recent development of novel resonant network antennas for new advanced large area or large volume plasma sources, an important step towards high performance plasmas and new fast processes is made.

Complex image method for RF antenna-plasma inductive coupling calculation in planar geometry. Part II: measurements on a resonant network

“…When excited at a resonance frequency, a RF resonant network develops very high currents within its structure, which can be used for inductively-coupled plasma (ICP) sources [2][3][4][5][6]. They are good candidates for large area processing, with a particular advantage because of their high and real input impedance.…”

A Simple Model for Ion Flux‐Energy Distribution Functions in Capacitively Coupled Radio‐Frequency Plasmas Driven by Arbitrary Voltage Waveforms

“…These plasmas provide unique opportunities to adjust the fluxes and impact energies of reactive and ionic species, which are most important for the processes at the surface. The typical discharge configurations are either geometrically asymmetric (a relatively small powered electrode in a large vacuum chamber) or geometrically symmetric (two large electrodes in a plane‐parallel setup), depending on the specific application . In the symmetric single‐frequency situation, the particle fluxes and energies are equal at both electrodes, whereas they differ from each other in an asymmetric situation.…”