Electron field emission characteristics from chemical vapor deposition (CVD
) diamond thin films implanted with nitrogen have been investigated. It is
shown that the formation of a stable emission from these films is character
ized by a three-stage process of breakdown of the implanted layer, activati
on of the emitter and turn-on of the stable emission. On the basis of the e
xperiment results, a modified activation model has been suggested to analyz
e the mechanisms of the emission. (C) 1999 Elsevier Science S.A. All rights
reserved.