High aspect ratio sharp nanotip for nanocantilever integration at CMOS compatible temperature

In this paper, we demonstrate a novel low temperature nanofabrication approach that enables the formation of ultra-sharp high aspect ratio (HAR) and high density nanotip structures and their integration onto nanoscale cantilever beams. The nanotip structure consists of a nanoscale thermally evaporated Cr Spindt tip on top of an amorphous silicon rod. An apex radius of the tip, as small as 2.5 nm, has been achieved, and is significantly smaller than any other Spindt tips reported so far. 100 nm wide tips with aspect ratio of more than 50 and tip density of more than 5 × 10⁹ tips cm^-2 have been fabricated. The HAR tips have been integrated onto an array of 460 nm wide cantilever beams with high precision and yield. In comparison with other approaches, this approach allows the integration of HAR sharp nanotips with nano-mechanical structures in a parallel and CMOS compatible fashion for the first time to our knowledge. Potential applications include on-chip high-speed atomic force microscopy and field emission devices.