Field emission from gated diamond arrays

Diamond field emitter arrays have been developed for use as cold electron s ources in fiat panel displays and high-power tubes. Diamond was selectively deposited on patterned silicon wafers, and the common problems of field em ission from the gate and the walls have been solved by innovative modificat ions in the processes involved. This resulted in cathodes where the gate ar ea was completely for of diamond. The leakage currents were less than 8% of the total current. The diamond cathodes were tested in two different diode configurations in a UHV system for voltages ranging from 0-20 V. Field emi ssion has been achieved at ultra-low onset voltages of less than 0.25 V and very high currents were obtained. For a voltage of 3 V applied to the gate , for example, corresponding to an electric field of 1.5 V/mu m, emission c urrents of up to 1 mA have been observed and tested for several days withou t deterioration. At 7 V, a current of 3.5 mA was achieved in this configura tion. The onset of field emission for measurements to a flat anode was 0.5 V/mu m, and 3.5 mA were reached at 0.8 V/mu m. (C) 1999 Elsevier Science B. V. All rights reserved.