Growth of polycrystalline diamond-films for low field electron emission

The potential for using diamond as a negative electron affinity (NEA) material was recognized by Himpsel et al. in 1979 and makes CVD diamond a promising candidate for cold-cathode applications and field emission displays. The current work shows one promising approach to utilize a double bias-assisted hot filament chemical vapor deposition (HFCVD) method for diamond growth. Selected area deposition of diamond films on tungsten wires is successfully achieved in the HFCVD system. Diamond tungsten wires show good electron field emission properties, that is, emission current density J/sub c/=2000 /spl mu/A/cm/sup 2/ (under 23.6 V//spl mu/m) and turn on field of F/sub 0/=12 V//spl mu/m. The effective work function (/spl Phi/) estimated by Fowler-Nordheim plot of the I-V characteristics is /spl Phi/=0.058 eV. The influence of different growth conditions on film quality has been investigated by micro-Raman measurements and optical microscopy.