THE STUDY FOR THE EFFECT OF HIGH PRESSURE AND DIFFERENCE CONCENTRATION OF CARBON ON NANODIAMOND FILM GROWTH

The influence of total gas pressure（20～26kPa）and methane concentration（0.3%～1%）on diamond growth using mixture gas of H₂/Ar/CH₄ source by microwave plasma chemical vapor deposition（MPCVD）was investigated.For a fixed methane concentration，characterization by Raman spectroscopy，scanning electron microscopy and X-ray diffraction indicated Characterization of nano diamond quality，surface morphology，grain size.The results show that growth rate increase with pressure increasing，but quality of nano-diamond films first become better then become worse while the pressure increases.Then using higher pressure and litter methane concentration could gain highly quality nanocrystalline diamond films.