Characterization of substrate-film interfaces for CVD diamond deposited on fused quartz and silicon substrates

The morphology and structure of CVD diamond films deposited on fused quartz substrates are described. Using films which had delaminated from the substrate it was possible to examine the morphology and composition of both the front and back surfaces. This examination, coupled with the Auger characterization of the surface of the substrate in the region from which the film had delaminated, showed that the interface is almost atomically sharp, with no evidence for the formation of amorphous carbon (a-C) or SiC interface layers. By contrast, the back surface of films grown on Si wafers showed clear evidence for the formation of an amorphous carbon interface layer. A novel aspect of this work is the use of Secondary Electron Emission (SEE) spectroscopy to characterize CVD diamond films. It turns out that the SEE spectrum is a much more sensitive probe than Auger for the characterization of carbon allotropes.