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Transmission electron microscopy and electron energy loss spectroscopy analysis of ultrathin amorphous carbon films

Published online by Cambridge University Press:  03 March 2011

D. Wan  and
K. Komvopoulos
D. Wan
Affiliation:
Department of Mechanical Engineering, University of California, Berkeley, California 94720
K. Komvopoulos
Affiliation:
Department of Mechanical Engineering, University of California, Berkeley, California 94720
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Abstract

Transmission electron microscopy (TEM) and analytic TEM were used to study the microstructure of amorphous carbon (a-C) films of thickness in the range of 5–100 nm deposited on Si(100) by radio-frequency (rf) sputtering. High-resolution cross-section TEM revealed a two-layer structure consisting of the a-C film and an ultrathin interface layer, in agreement with electron energy loss spectroscopy results. The presence of a 35-Å-thick interface layer (regardless of the deposition conditions) indicates that nucleation and initial growth of the a-C films were mainly controlled by the substrate surface condition. Mass-thickness contrast in bright-field TEM images showed an interface layer denser than the a-C film. This layer, believed to consist of Si, a-C, and SiC, enhances the adhesion of the film to the silicon substrate and accommodates the residual stress in the film. High-resolution cross-section TEM images revealed the presence of platelike nanocrystallites (∼35 Å in size) randomly distributed in the a-C film and oriented parallel to the surface. The possible mechanisms leading to the formation of these nanocrystalline structures are discussed in terms of sputtering phenomena occurring during film deposition.

Keywords

MicrostructureThin filmAmorphous
Type
Articles
Information
Journal of Materials Research , Volume 19 , Issue 7 , July 2004 , pp. 2131 - 2136
Copyright
Copyright © Materials Research Society 2004

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