Measurement of inverted n-hexane fireball properties with a Multipole Resonance Probe

  • Gerhard Eichenhofer 4-A Plasma GmbH
  • Moritz Oberberg Institute of Electrical Engineering and Plasma Technology, University of Bochum, Universitätsstraße 150, 44801 Bochum, Germany
  • Jörg Eisenlohr
  • Peter Awakowicz Institute of Electrical Engineering and Plasma Technology, University of Bochum, Universitätsstraße 150, 44801 Bochum, Germany
  • Johannes Grünwald Gruenwald Laboratories GmbH, Taxberg 50, 5660 Taxenbach, Austria

Abstract

In this paper we present for the first time the measurement of inverted fireballs in a low-pressure
Ar/n-hexane plasma by using a Multipole Resonance Probe. The basic plasma parameters such
as electron density, electron temperature and Debye length as well as the particle collision
frequency have been obtained for different experimental settings. These measurements show
that inverted fireballs that are created in chemically active plasma offer advantageous properties
regarding deposition techniques. Furthermore, the influence of the plasma parameters on grid
bias and changes in neutral gas pressure has been studied within this work. It is observed that
the plasma density within an inverted fireball configuration can be raised by more than an order
of magnitude compared to the background plasma or without biasing the grid electrode,
respectively.