Field-Emission Cathodes Based on Microchannel Plates

Abstract

The existing methods of fabricating low-field cathodes do not permit the development of device structures that comply with the requirements of developers of systems. In this work, large-area field-emission cathodes with homogeneous emission properties of the working surface and low working voltages (<1 kV) are considered. A Spindt cathode with a number of silicon microtips up to 6000 and a packing density of ~1 × 10⁵ cm^–2 is investigated. Titanium nitride and carbon films are deposited onto microtips using the electric-arc method. It is shown that the cathode has low emission homogeneity due to the problem of reproducing microtips of the same shape and size. A cathode based on a microchannel plate with channels 6 μm in diameter, inside which graphite-like nanostructures are formed by the electric-arc method, is fabricated. It is found that an increase in the electron flux in the channels of a microchannel plate can result in a considerable decrease in the operating voltage (<1 kV) and attain high emission homogeneity at the highest admissible output current.