The atomic bonding configurations of carbon bonding in diamond and diamondlike thin films are explored using Raman scattering. The general aspects of Raman scattering from composites are presented. Effects are discussed due to crystalline or amorphous structures, large versus microcrystalline domains, and strong optical absorption and transparent regions. The Raman scattering from diamondlike films shows several features which are attributed to microcrystalline graphitelike structures which all originate from the same region in the sample. In contrast, the spectra of diamond films show features attributed to different components of a composite film. Components identified are crystalline diamond, and disordered and microcrystalline graphitic structures. The presence of precursor microcrystalline or amorphous diamond structures is also suggested.

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Raman scattering measurements are used to characterize the components of microcrystalline Si and carbon films. A model is described which addresses the properties of Raman scattering from composites of materials of different optical absorption. The analysis shows that the observed spectra are dependent on both the percentage of the components and on the domain size of the more highly absorbing domains. Carbon films produced by different enhanced CVD techniques show both sp2 (graphite) and sp3 (diamond) regions. Silicon films prepared by excimer laser exposure of hydrogenated a-Si and by magnetron sputtering showed features due to both microcrystalline and amorphous regions. The experimental results reflect the length scales of the domains and vibrational excitations.

Raman spectroscopy has been used to examine diamond thin films produced by various CVD processes. The Raman spectra exhibit, features which suggest that the films are composites of diamond (sip)) and graphite -like (sp) bonding. A brief outline of Raman scattering from composites is presented. A first attempt at modeling these types of films using composites of diamond and graphite powders is reported. It is found that the Raman features associated with sp bonding in the films do not correlate well to features exhibited by microcrystalline graphite.