Change from micrometre to nanometre size for diamond grains by plasma chemical vapour deposition

摘要

Nanocrystalline diamond (NCD) films were deposited using CH4 and H2 gas mixtures by the electron assisted chemical vapour deposition (EACVD) method at 640 and 400 deg C, and microcrystalline diamond film was simultaneously synthesized at 890 deg C. The size of NCD was estimated as about 8-100 nm according to electron micrographs and the full width at half maximum of diamond features of x-ray diffraction spectra. We have investigated the local gas environments where diamond films were deposited using a quadrupole mass spectrometer. It shows that the growth temperature and local gas environment are two important factors influencing diamond grain size.