Structures and processes for fabricating field emission cathode tips using secondary cusp
AssigneeInternational Business Machines Corporation
InventorSteven M. Zimmerman
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Abstract
The present invention relates generally to new structures for a field emission cathode and processes for fabricating the same. The field emission is made of any material that is capable of emitting electrons under the influence of an electrical potential. The field emission cathode has several unique three dimensional structures. The basic structure comprises of a layer of material with cathode tips. For a more complex structure the cathode tip is preferably accurately aligned inside an extraction/control electrode structure, in preferably a vacuum environment. The structures of this invention can be fabricated to be connected to other similar field emission cathodes or to other electronic devices.
Claims51
A field emission cathode structure comprising at least one layer of material which is capable of emitting electrons under the influence of an electric field, and having at least one tip for the emission of electrons formed by the process comprising the steps of:
- (a) providing at least one hole in a substrate,
- (b) depositing at least a first material and filling at least a portion of said hole sufficiently to form a cusp,
- (c) depositing said at least one layer of a material which is capable of emitting electrons under the influence of an electrical field, and filling at least a portion of said cusp to form said at least one electron emitting layer, wherein said electron emitting layer has an upper surface and a lower surface, said upper surface having at least one secondary cusp, said lower surface having at least one tip, such that at least one tip is opposite said at least one secondary cusp, and wherein at least a portion of the surface of said tip is concave and wherein said at least one tip is used for the emission of said electrons, and
- (d) removing at least a portion of said substrate and at least a portion of said first material to expose at least a portion of said tip of said electron-emitting material and thereby forming said at least one field emission cathode structure.
A field emission cathode structure comprising at least one layer of material which is capable of emitting electrons under the influence of an electric field, and having at least one tip for the emission of electrons formed by the process comprising the steps of:
- (a) forming at least one layer of an electrically conductive material over a base layer,
- (b) forming at least one hole at least through said at least one electrically conductive layer,
- (c) depositing at least one insulative material over said at least one electrically conductive layer and filling at least a portion of said hole sufficiently to form a cusp,
- (d) depositing at least one layer of a material which is capable of emitting electrons under the influence of an electrical field, over said at least one insulative material of step (c), and filling at least a portion of said cusp to form said at least one electron emitting layer, wherein said electron emitting layer has an upper surface and a lower surface, said upper surface having at least one secondary cusp, said lower surface having at least one tip, such that at least one tip is opposite said at least one secondary cusp, and wherein at least a portion of the surface of said tip is concave and wherein said at least one tip is used for the emission of said electrons, and
- (e) removing at least a portion of said material underneath said tip to expose at least a portion of said tip of said electron-emitting material and thereby forming said at least one field emission cathode structure.
A field emission cathode structure comprising at least one layer of material which is capable of emitting electrons under the influence of an electric field, and having at least one tip for the emission of electrons formed by the process comprising the steps of:
- (a) forming a plurality of layers of electrically conductive material over a base layer, such that each said layer of electrically conductive material is separated by an insulative material,
- (b) forming at least one hole at least through said electrically conductive layers,
- (c) depositing at least one insulative material over said layers of electrically conductive material and filling at least a portion of said hole sufficiently to form a cusp,
- (d) depositing at least one layer of a material which is capable of emitting electrons under the influence of an electrical field, over said insulative material of step (c), and filling at least a portion of said cusp to form said at least one electron emitting layer, wherein said electron emitting layer has an upper surface and a lower surface, said upper surface having at least one secondary cusp, said lower surface having at least one tip, such that at least one tip is opposite said at least one secondary cusp, and wherein at least a portion of the surface of said tip is concave and wherein said at least one tip is used for the emission of said electrons, and
- (e) removing at least a portion of material underneath said tip to expose at least a portion of said tip of said electron-emitting material and thereby forming said at least one field emission cathode structure.
A field emission cathode structure comprising at least one layer of material which is capable of emitting electrons under the influence of an electric field, and having at least one tip for the emission of electrons, wherein said electron emitting layer has an upper surface and a lower surface, said upper surface having at least one secondary cusp, said lower surface having at least one tip, such that at least one tip is opposite said at least one secondary cusp, and wherein at least a portion of the surface of said tip is concave and wherein said at least one tip is used for the emission of said electrons, and thereby forming said at least one field emission cathode structure.
Dependencies are inferred from the claim text.