Characteristics of ultra-nano-crystalline diamond films grown on the porous anodic alumina template

Nanodiamond films containing uniformly small diamond grains (< 20 nm) were synthesized using porous anodic alumina (PAA) as template in conjunction with bias-enhanced nucleation growth (BEG) process. PAA with uniform pore size distribution is required and the bottom of channel should be free of residual alumina layer for the purpose of effectively nucleating diamond seeds. Thus obtained PAA-patterns can then effectively enhance the formation of diamond nuclei, resulting in patterned nanodiamond films, which possess superior electron field emission properties to the non-patterned nanodiamond films. Benefit of PAA patterning process on improving the electron field emission properties of the nanodiamond films is ascribed to the suppression on the formation of trans-polyacetylene layer and the presence of hillock structure, which facilitates the electron transport from Si surface to top surface of nanodiamond.