US 5,181,874 AGranted

Method of making microelectronic field emission device with air bridge anode

AssigneeHughes Aircraft Company

InventorsMarko Sokolich, Zaher Bardai

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Abstract

A field emission device employs an anode in the form of an air bridge spanning the tip of a field emission cathode. The anode is supported only at its opposite ends, leaving the area under the air bridge open. An array of cathode emitters employ a series of parallel, laterally spaced anode air bridges, with each air bridge spanning a line of cathodes. The lateral spacing between the air bridges facilitates both the removal of underlying photo-resist during fabrication, and the establishment of a uniform vacuum if desired. The clearance between the anode and cathode is substantially less than previously obtainable, resulting in a significant reduction in both size and in the anode's operating voltage level. Fabrication of the air bridge anodes can be integrtaed with the remainder of an integrated circuit.

Claims1

Dependent claims

A method of making a field emission device, the field emission device comprising a substrate, an array of field emission tips on the substrate and a plurality of rows of conductive air bridges spanning the array of field emission tips, wherein the air bridges are formed by the process comprising the steps of:

depositing a first layer of photoresist over the substrate covering the field emission tips;
forming openings in the first layer, the openings having the shape and spacing of the air bridges;
forming a metallic membrane over the openings to form a plating base for the air bridges;
forming a second layer of photoresist over the substrate covering the metallic membrane and exposed portions of the first layer;
forming second openings in the second layer, the second openings having the shape and spacing of the air bridges and exposing portions of the metallic membrane;
forming a metal layer over the second openings;
and
removing the remaining portions of the first and second layers.

5 more elements

Dependencies are inferred from the claim text.

Facts

Application: 07/865,384Filed 8 Apr 1992 · division
Priority: 26 Mar 1991
Granted: 26 Jan 1993
Term ends: Not estimatedThe source records don’t support an estimate.

Classification4 codes

H01J 3/022
Electron guns using a field emission, photo emission, or secondary emission electron source: with microengineered cathode, e.g. Spindt-type
H01J 9/025
Of cold cathodes: of field emission cathodes
H01J 21/105
With one or more immovable internal control electrodes, e.g. triode, pentode, octode: with microengineered cathode and control electrodes, e.g.…
H01J
Electric discharge tubes or discharge lamps