Theoretical analysis of field emission from a metal diamond cold cathode emitter

Recently, Gels et al. [J. Vac. Sci. Technol. B 14, 2060 (1996)] proposed a cold cathode emitter based on a Spindt-type design using a diamond film doped by substitutional nitrogen. The device is characterized by high field emission currents at very low power. Two properties, the rough surface of the metallic injector and the negative electron affinity of the (111) surface of the diamond are essential for its operation. We present a first consistent quantitative theory of the operation of a Geis-Spindt diamond field emitter. Its essential features are predicated on nearly zero-field conditions in the diamond beyond the depletion layer, quasiballistic transport in the conduction band, and applicability of a modified Fowler-Nordheim equation to the transmission of electrons through the Schottky barrier at the metal-diamond interface. Calculated results are in good qualitative and quantitative agreement with the experimental results of Gels et al. (C) 1997 American Vacuum Society.