Bell Communications Research, Inc.

Tirunelveli S Ravi

Robert B Marcus

Brian G Bagley

Nicholas C Andreadakis

A method of fabricating a self-aligned gated electron field emitter. An oxidation process forms an optimized, atomically sharp needle (18) in a silicon substrate (12). The needle and surrounding planar area are conformally coated with silicon dioxide (22). A dielectric layer (24) is deposited and planarized over the needle. The dielectric layer is then partially etched away so as to expose the coated needle. The silicon dioxide exposed on the needle is isotropically etched so as to undercut the dielectric layer. A gate metal is directionally deposited so as to form a gate layer (26) on the planar portions of the dielectric layer that is electrically isolated from the gate metal (28) deposited on the needle. The metal on the needle is anodically etched by applying the potential only to the silicon and not to the gate layer. Electro-plating may recoat the needle with another metal (30). The silicon substrate may be replaced by a glass substrate (42) on which is deposited a polysilicon or amorphous silicon layer (40). The invention allows the fabrication of an array of emitters with closely spaced gates over large areas and on inexpensive substrates.

Self-aligned gated electron field emitter

Tapered silicon structures, of interest for use, e.g., in atomic force microscopes, in field-emission devices, and in solid-state devices are made using silicon processing technology. Resulting tapered structures have, at their tip, a radius of curvature of 10 nanometers or less.

Device including a tapered microminiature silicon structure

In a structure comprising an ultra-sharp silicon tip coated with a layer of material, the silicon is removed from the structure. The remaining material is utilized as a mold. Metal deposited in the mold replicates the original silicone tip. In this way, ultra-sharp all-metal tips suitable, for example, as field-emitter sources are provided.

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Eatontown, NJ, United States of America

Tirunelveli S Ravi