Ly. Khriachtchev et al., INTERFERENCE-INDUCED EFFECTS IN RAMAN STUDIES OF HYDROGEN-FREE DIAMOND-LIKE CARBON-FILMS, DIAMOND AND RELATED MATERIALS, 7(10), 1998, pp. 1451-1458
In transparent hydrogen-free diamond-like carbon films, two types of i
nterference-induced effects on Raman spectra are observed, amplitude e
nhancement and spectral modification. Specific features of the interfe
rence effects on Raman intensity components detected from different co
nstituents of the samples, which are the film surface, diamond-like bu
lk, and silicon substrate, are considered. The proportion between thes
e Raman components is shown to be an oscillating function of the film
thickness. A procedure to record selectively Raman scattering from bul
k structure is proposed, and a discrimination factor of approx. 10(-2)
for the surface scattering is experimentally demonstrated. The thickn
ess dependency of the Raman intensity allows the absorption coefficien
t of the bulk material to be estimated. The observed modification of t
he Raman spectra influences the characterization of film microstructur
e. (C) 1998 Elsevier Science S.A. All rights reserved.