ELECTRON FIELD-EMISSION FROM DIAMOND TIPS PREPARED BY ION SPUTTERING

In this letter we report the field emission from cones etched into a s ynthetic-type IIb (100) oriented boron-doped diamond crystal. The cone s were produced with an ion sputtering process. With a high-resolution scanning electron microscope we found the curvature radius at the end of the cones to be less than 10 nm. The length of these cones is in t he range of 10 mu m giving a field enhancement of approx. 1000. Field emission started at field strength of 2 V/mu m, and at 3.8 V/mu m 10 n A were measured using a spherical anode of 4 mm diam. From a Fowler-No rdheim fit the work function could be deduced to be 3-4 eV. Hence, ele ctrons are emitted from the valence band. (C) 1996 American Institute of Physics.