US 5,312,777 AGranted

Fabrication methods for bidirectional field emission devices and storage structures

AssigneeInternational Business Machines Corporation

InventorsJohn E. Cronin, Kent E. Morrett, Michael D. Potter, Matthew J. Rutten

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Abstract

Bidirectional field emission devices (FEDs) and associated fabrication methods are described. A basic device includes a first unitary field emission structure and an adjacently positioned, second unitary field emission structure. The first unitary structure has a first cathode portion and a first anode portion, while the second unitary structure has a second cathode portion and a second anode portion. The structures are positioned such that the first cathode portion opposes the second anode portion so that electrons may flow by field emission thereto and the second cathode portion opposes the first anode portion, again so that electrons may flow by field emission thereto. A control mechanism defines whether the device is active, while biasing voltages applied to the first and second unitary structures define the direction of current flow. Multiple applications exist for such a bidirectional FED. For example, an FED DRAM cell is discussed, as are methods for fabricating the various devices.

Claims8

Dependent claims

A method for forming a bidirectional field emission device, comprising the steps of:

(a) providing a substrate having an upper surface;
(b) forming a first cathode portion above the upper surface of said substrate so as to extend substantially parallel thereto;
(c) forming a second cathode portion above said first cathode portion so as to extend substantially parallel thereto;
(d) forming a first anode portion and a second anode portion, said first anode portion being formed to couple with said first cathode portion so as to define a first unitary field emission structure, and said second anode portion being formed to couple with said second cathode portion so as to define a second unitary field emission structure, said first unitary field emission structure and said second unitary field emission structure being adjacently disposed such that said first cathode portion is spaced from and opposes said second anode portion so that electrons may flow by field emission from said first cathode portion of said first unitary field emission structure to said second anode portion of said second unitary field emission structure, and such that said second cathode portion is spaced from and opposes said first anode portion so that electrons may flow by field emission from said second cathode portion of said second unitary field emission structure to said first anode portion of said first unitary field emission structure;
and
(e) forming metallizations for controlling the emission of electrons from said first cathode portion of said first unitary field emission structure and from said second cathode portion of said second unitary field emission structure by applying biasing voltages to said first unitary field emission structure and said second unitary field emission structure.

3 more elements

Dependencies are inferred from the claim text.