ELECTRICAL CHARACTERIZATION OF DIAMOND AND GRAPHITE COATED MO FIELD EMITTERS

Citation
Mt. Mcclure et al., ELECTRICAL CHARACTERIZATION OF DIAMOND AND GRAPHITE COATED MO FIELD EMITTERS, Journal of vacuum science & technology. B, Microelectronics and nanometer structures processing, measurement and phenomena, 15(6), 1997, pp. 2067-2071
Citations number
19
ISSN journal
10711023
Volume
15
Issue
6
Year of publication
1997
Pages
2067 - 2071
Database
ISI
SICI code
1071-1023(1997)15:6<2067:ECODAG>2.0.ZU;2-3
Abstract
Current-voltage characteristics of tip-shaped molybdenum field emitter s were investigated before and after coating with diamond or graphite powders. Stable emission was observed only after annealing and formati on of a conductive Mo carbide layer at the metal-coating interface. Bo th coated emitters displayed enhanced emission and ''turn-on'' voltage s reduced by a factor of 2 as compared to the uncoated emitters. For t he graphite coated emitter, the enhancement was attributed to an incre ase in the field enhancement factor due to the coating morphology. Rou ghening of the Mo-diamond interface via carbide formation during the a nnealing step was presumed to have been the cause for the enhanced emi ssion for the diamond coated emitter. The transmission probabilities f or the Mo-diamond and diamond-vacuum interfaces were calculated, using the WKB method, based on an emission mechanism from the intrinsic dia mond's conduction band minimum. With a field locally enhanced to 10(8) V/cm, the transmission probability for the diamond-vacuum interface w as 10(8) times larger than that of the Mo-diamond interface. This eval uation confirmed that the electron affinity of the diamond surface is not a governing factor in the emission from intrinsic diamond. (C) 199 7 American Vacuum Society.