IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Plasma Science Monday Sessions
       Session PS-MoP

Paper PS-MoP5
A Multi-Technique Investigation of the Pulsed Plasma and Plasma Polymers of Acrylic Acid, Propanoic Acid and Hexamethylenedisiloxane

Monday, October 29, 2001, 5:30 pm, Room 134/135

Session: Plasma Diagnostics and Plasma-Surface Interactions Poster Session
Presenter: S. Fraser, University of Sheffield, England
Authors: S. Fraser, University of Sheffield, England
D. Barton, University of Sheffield, England
A.J. Roberts, Kratos Analytical, England
R.D. Short, University of Sheffield, England
Correspondent: Click to Email
The synthesis of thin plasma polymer films from radio frequency (rf) sustained glow discharges of small organic compounds is well documented. Films containing a high degree of retention of the starting monomers original functionality and structure can be deposited using a low power plasma. These plasmas can be sustained by continuous wave (CW) or by pulsing a higher input power to achieve a lower average power. Plasma polymers of acrylic acid, propanoic acid and hexamethylenedisiloxane have been fabricated from pulsed 13.56 MHz RF plasmas in a "capicatively" coupled plasma deposition chamber. Plasma "on" and "off" (t@sub on/off@) times in the millisecond (ms) pulse time regime have been investigated using a peak plasma power of 50 W. Employing a fixed ton (5ms) the effect of toff (0-2000 ms) on the solid-phase plasma polymer has been investigated using X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF SIMS). Mass spectrometry has been employed to monitor the neutral and charged species in the plasma-gas as a function of toff and deposition rates have been monitored by means of a quartz crystal mass balance (QCMB). For comparison continuous (CW) wave plasmas of equivalent "average power" have been studied. The XPS (C1s core line) show that with increased t@sub off@ the extent of functional group retention increased. Valence band XPS and SIMS data indicate at low "average" powers (0.2 W) a linear polymer, closely resembling the conventional polymer, is deposited. The mass spectral data indicate the principal affect of t@sub off@ is on the amount of intact monomer in the system. For example, with acrylic acid this was shown by monitoring the signal from the molecular ion of acrylic acid (m/z 72) in the neutrals.