Crystal orientation distribution in highly oriented diamond films investigated by SEM and TEM

Orientation imaging techniques based on electron backscattering diffraction (EBSD) and convergent beam electron diffraction (CBED) pattern acquisition carried out respectively in the scanning electron microscope (SEM) and in the transmission electron microscope (TEM) were used to characterise the orientation of crystals in two highly oriented diamond (HOD) films with different thicknesses. The substrate surface modification has been also investigated by EBSD. The films were synthesised on Si(100) in a microwave plasma chemical vapor deposition (MPCVD) reactor where nucleation is initiated via an in situ pretreatment consisting in a carburization step followed by a bias enhanced nucleation (BEN). For the thin film EBSD allowed to highlight the presence of alpha-SiC on the silicon substrate as well as to evaluate their epitaxial relationship. The TEM-based system allowed to obtain more accurate misorientation data of the fine grained diamond structure corresponding to the first stages of growth. For the thicker film, EBSD was used to determine the mosaicity at the surface.