- Evans, Ryan D. and Doll, Gary L. and Morrison Jr, Philip W. and Bentley, James and More, Karren L. and Glass, Jeffrey T., The effects of structure, composition, and chemical bonding on the mechanical properties of Si-aC:H thin films,
Surface and Coatings Technology, vol. 157 no. 2-3
pp. 197 - 206 [S0257-8972(02)00164-0] .
(last updated on 2007/04/17)
The objective of this study was to correlate mechanical properties with the structure and chemistry of silicon-incorporated amorphous hydrocarbon (Si-aC:H) films deposited by reactive sputtering. Hardness and elastic modulus were measured via microindentation, and intrinsic compressive stress was determined from radius-of-curvature measurements using surface mapping microscopy. Film chemistry was investigated with X-ray photoelectron spectroscopy, electron energy-loss spectroscopy, Raman spectroscopy, and attenuated total reflection Fourier transform infrared spectroscopy. Conventional- and high-resolution transmission electron microscopy revealed that the Si-aC:H phase is amorphous and TiC exists at the Si-aC:H/Ti phase boundary. Mechanical properties such as hardness, modulus, and intrinsic stress decreased with increasing Si and H content in the films, for Si/C greater than or equal 0.04. Measurements show that this is most likely due to a decrease in C-C sp3 bonds, accompanied by an increase in C-Si and C-H bonds. In addition, the Si-aC:H film with Si/C = 0.04 is fundamentally different from the other Si-aC:H films with higher Si and H contents. It is concluded that a film with diamond-like carbon characteristics can be deposited using a low tetramethyl silane (TMS) flow rate, such that Si/C = 0.04 in the film. However, films deposited with higher TMS flow rates (such that Si/C greater than or equal 0.06 in the films) are more characteristic of amorphous hydrogenated silicon carbide. © 2002 Elsevier Science B.V. All rights reserved.
Diamond like carbon films;Silicon compounds;Thin films;Mechanical properties;Chemical bonds;Sputtering;Spectroscopy;Fourier transforms;