Emission characteristics of NbC/Nb field emitters

We report on an extensive study of the emission characteristics (noise and stability) of these NbC/Nb emitters at currents of /spl sim/1 /spl mu/mA and in residual pressure ranging from 3/spl times/10/sup -9/ to 3/spl times/10/sup -6/ Torr for seven different gases, Ar, C/sub 2/H/sub 2/, CH/sub 4/, CO, H/sub 2/, H/sub 2/O and O/sub 2/. These array tips are individually addressable so we can study and compare the emission characteristics of single emitters. The emitting surface is rough and contaminated, and the emission comes from a variable number of nanoprotrusions. Consequently the emission is much less stable than it would be for a clean smooth emitter. But our measurements are representative of the real world of microelectronics arrays.