Field-emission characteristics of chemical vapor deposition-diamond films

Discontinuous and continuous diamond films with different morphologies and qualities were deposited on n(2+)-type Si(100) substrates, using the hot-fi lament chemical vapor deposition (CVD) technique from CH4-H-2 gas mixtures. The field-emission characteristics of these diamond films were investigate d. The rum-on fields at a 0.01mA/cm(2) current density were recorded for al l the tested CVD-diamond films. It was found that discontinuous diamond fil ms showed a much lower turn-on field (1.2 V/mu m) than continuous ones (20 V/mu m). The effective working function of continuous diamond films was aro und 0.1 eV, while that for discontinuous diamond films is about 0.03 eV. O- 2 plasma post-deposition sharpening of thick diamond films indicated that t he geometrical-field enhancement, caused by the surface topographic changes , has no significant influence on the turn-on field. (C) 2000 Elsevier Scie nce S.A. All rights reserved.