Fabrication of nano-tips by carbon contamination in a scanning electron microscope for use in scanning probe microscopy and field emission

Results are reported on a systematic study addressed to an effective fabrication of nano-tips by means of carbon contamination in a scanning electron microscope. Nano-tips with angular aperture of 10 degrees, apical radius of about 5 nm, 1 mu m long can be efficiently produced by our method in less than 60 s of electron beam exposure; it involves, in particular, successive focusing during tip growth and the use of a carbon block as a source of contaminant. These tips have been used as high aspect ratio and low capillary force probes in atomic force microscopy, and as nano-sized field emitters for electron guns.