Plasma etching of organic material: Combined effects of charged and neutral species

¹ Laboratoire Plasma et Conversion d'Énergie, Université de Toulouse, CNRS, 118 route de Narbonne, 31062 Toulouse Cedex 4, France
² Laboratoire des Polymères Colloïdes et Interfaces, Université du Maine, 1 avenue Olivier Messiaen, 72085 Le Mans Cedex 9, France

Corresponding author: richard.murillo@laplace.ups-tlse.fr

Received: 17 November 2006
Accepted: 29 November 2006
Published online: 7 February 2007

Abstract

A model organic material, namely the 36-n-alkane hexatriacontane, was etched in a dissymmetrical parallel plate RF plasma reactor and a dual distributed electron cyclotron resonance (DECR) plasma reactor, in different O₂-Ar mixtures. A specific attention was paid to the role of the ion bombardment, especially when its effect is combined with the chemically active species created in an oxygen discharge. The discharge was monitored by optical emission spectroscopy (OES). The modifications induced by plasma treatment on the structure of the material were analysed by Fourier transform infrared spectroscopy (FTIR), steric exclusion chromatography (SEC) and composition analysis. We found that the ion bombardment has not only a sputtering effect but also enhances the reaction rate of the chemical species on the layer surface. It appears that plasma treatment leads to cross-linking and recombination with molecules from the room atmosphere.