Synthesis and electron field emission of nanocrystalline diamond thin films grown from N2/CH4 microwave plasmas

Nanocrystalline diamond films have been synthesized by microwave plasma enhanced chemical vapor deposition using ${\mathrm{N}}_{\mathrm{2}}{\mathrm{/CH}}_{\mathrm{4}}$ as the reactant gas without additional ${\mathrm{H}}_{\mathrm{2}}.$ The nanocrystalline diamond phase has been identified by x-ray diffraction and transmission electron microscopy analyses. High resolution secondary ion mass spectroscopy has been employed to measure incorporated nitrogen concentrations up to ${\text{8×10}}^{20}\hspace{0.17em}{\mathrm{atoms/cm}}^{\mathrm{3}}.$ Electron field emission measurements give an onset field as low as $\text{3.2\hspace{0.17em}}\mathrm{V/\mu m}.$ The effect of the incorporated nitrogen on the field emission characteristics of the nanocrystalline films is discussed.