Characterization of electron emission from N-doped diamond using simultaneous field emission and photoemission technique

Nitrogen (N)-doped diamond films have been grown by hot filament chemical vapor deposition (CVD) technique using urea (NH2)(2)CO) as a dopant. The bulk and surface of the film are identified as diamond from the results of reflection high energy electron diffraction (RHEED), Auger electron spectroscopy (AES), reflective electron energy loss spectroscopy (REELS) and Raman spectroscopy, while the N concentration is confirmed to be of the order of 10(20) cm(-3) from Rutherford backscattering (RBS) and X-ray photoelectron spectroscopy (XPS) measurements. The threshold field for field emission from the films has been reported to be about 0.5 V/mu m. The origin of the electronic states and the related characteristics of field emission from heavily N-doped diamond using the technique of simultaneous field emission and photoemission (FEPES) has been discussed. The FEPES result for the N-doped diamond suggests that after an activation procedure, there is a decrease in the required applied field together with a change in the field emission from the valence band edge to the Fermi level, indicating that metallic states at the surface dominate field emission. (C) 1999 Elsevier Science B.V. All rights reserved.