The growth aspects of nanocrystalline diamond films and their effects on electron emissions

In this paper, aspects of the growth of nanocrystalline diamond films using CH/sub 4//H/sub 2//N/sub 2/ microwave plasma chemical vapor deposition and their behavior as electron field emission cathode were reported. Nanocrystalline diamond films with "cauliflower-like" morphology were investigated for field emission in vacuum. The presence of more sp/sup 2/-bonded non-diamond carbon content and a higher electrical conductivity of the film enhanced the field emission characteristics were observed, while a reduction in the grain size of the diamond had no similar effect. For field emission characterization, nanodiamond films were grown using methane flow rate varying between 2 seem and 15 seem, with electrical resistance from 10 /spl Omega/ to hundreds of M/spl Omega/, and grain size in the range of 5 nm to 200 nm were employed.