The present invention deals with the generation of sharp single crystal diamond
tips and the arrays of these tips, and their fabrication technology. The invention
combines the deposition of synthetic diamond films with reactive etching processes.
Upon the diamond orientation prepared and reactive etching environment with considerable
directivity of ions, single crystal diamond tips with different apical angles can
be fabricated. Very sharp diamond tips with an apical angle of no more than about
28 and a tip radius smaller than 50 nm are fabricated on pyramidal-shaped
[001]-textured diamond films by subsequent reactive etching., The technology is
based on selective etching of sp2- and sp3- hybridized carbons
by the activated constituents of an etching environment, in particular based on
atomic hydrogen, in a way similar to ion bombardment, which contributes to overall
etching and local conversion of diamond to graphitic phase promoting further etching
with chemically activated species. This novel method is capable of forming diamond
tip arrays over large areas with great uniformity and high reproducibility. The
diamond tips prepared are single diamond crystals with their [001] axes parallel
each other and normal to the substrate surface. The invented technology enables
the control of the apical angle, radius and density of the diamond tips.
