SEM and Raman analysis of boron-doped diamond coating on spherical textured substrates

Abstract

In this work boron-doped diamond (BDD) films were grown on new geometric form substrate. A laser texturized pretreatment on these substrates has promoted a better adherence between film and substrate, and a decrease of diamond total stress. Films morphology, obtained from Scanning Electron Microscopy (SEM) images, have showed that diamond average grain size, between 10–15 μm, decreased when the boron doping level was increased. For the micro-Raman spectroscopy, spectra analyses performed on each sample have allowed the residual stress evaluation and the diamond purity, from diamond and graphitic Raman peaks shifts. In these films, residual stress increased from 0.2 to 1.2 GPa and diamond purity decreased from 99.6% to 92.6% as the doping level increased. A specific study of morphology, total stress and diamond purity as a function of methane concentration was done for diamond film doped with 10,000 ppm B / C. It was observed a significant increase of grain size and total stress but little variation of diamond purity as methane concentration was increased. All these results gave us support for the use of these devices in different applications.