The effect of PECVD plasma decomposition on the wettability and dielectric constant changes in silicon modified DLC films for potential MEMS and low stiction applications
- Thin Film Centre, University of the West of Scotland, Paisley Campus, High Street, Paisley PA1 2BE, Scotland (United Kingdom)
- Nanotechnology Institute, School of Electrical and Mechanical Engineering, University of Ulster, Northern Ireland (United Kingdom)
We have carried out investigations aimed at understanding the mechanism responsible for a water contact angle increase of up to ten degrees and a decrease in dielectric constant in silicon modified hydrogenated amorphous carbon films compared to unmodified hydrogenated amorphous carbon films. Our investigations based on surface chemical constituent analysis using Raman spectroscopy, x-ray photoelectron spectroscopy (XPS), SIMS, FTIR, contact angle / surface energy measurements and spectroscopic ellipsometry suggests the presence of hydrophobic chemical entities on the surface of the films. This observation is consistent with earlier theoretical plasma chemistry predictions and observed Raman peak shifts in the films. These surface hydrophobic entities also have a lower polarizability than the bonds in the un-modified films thereby reducing the dielectric constant of the silicon modified films measured by spectroscopic ellipsometry. Ellipsometric dielectric constant measurement is directly related to the surface energy through Hamaker's constant. Our current finding is expected to be of benefit to understanding stiction, friction and lubrication in areas that range from nano-tribology to microfluidics.
- OSTI ID:
- 22107637
- Journal Information:
- AIP Advances, Vol. 2, Issue 3; Other Information: (c) 2012 Copyright 2012 Author(s). This article is distributed under a Creative Commons Attribution 3.0 Unported License.; Country of input: International Atomic Energy Agency (IAEA); ISSN 2158-3226
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
CHEMICAL VAPOR DEPOSITION
DECOMPOSITION
DIAMONDS
ELECTROMECHANICS
ELLIPSOMETRY
FOURIER TRANSFORMATION
INFRARED SPECTRA
MASS SPECTRA
PERMITTIVITY
PLASMA
POLARIZABILITY
RAMAN SPECTRA
RAMAN SPECTROSCOPY
SILICON
SURFACE ENERGY
SURFACES
THIN FILMS
X-RAY PHOTOELECTRON SPECTROSCOPY