Controllable Growth of Nanocrystalline Diamond Films by Hot-Filament Chemical Vapor Deposition Method

Nanocrystalline diamond (NCD) films are deposited on Si wafer by using bias-assisted hot-filament chemical vapor deposition (HFCVD) method. The average grain size was controllable by varying CH, concentration. The scanning electron microscopy (SEM), Raman scattering spectroscopy and X-ray diffraction (XRD) were used to investigate the morphology, phase purity, and crystallinity of NCD films, respectively. Furthermore, we found that the morphological evolving of NCD films was corresponding to the variation of bias current, which might have close relation to thermal field electrons emission from NCD films at high temperature during the growth process, and then the related mechanism was discussed.