Field emission from nanotips

Nanotips are nanometre-size protrusions ending in one atom that are obtained from the concomitant action of temperature and high electric field. The properties of the emitted e-beams have been experimentally measured, i.e., energy distribution, current stability, level of coherence, or angular beam opening. They show characteristics which are associated to the atomic size of the nanotips. By correlation with the measured nanotip behaviour, the field emission characteristics we have measured from Spindt-type integrated microtip arrays are explained as being due to the emission from non-controlled nanoprotrusions along the microtip shanks. The use of the nanotip as a point source in a projection microscope allows a resolution of 0.5 nm for energies in the range of 200 V.