City University of Hong Kong

Chit Yiu Chan

Shuit-Tong Lee

Wenjun Zhang

Igor Bello

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&#xb0; 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 sp- and sp- 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.

Growing community of inventors

Hong Kong, China

Chit Yiu Chan