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US5372973A
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Method to form self-aligned gate structures around cold cathode emitter tips using chemical mechanical polishing technology
Assignee: Micron Technology Inc
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Filing: 1993-04-27
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Granted: 1994-12-13
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Expires: 2013-04-27
Abstract
Abstract A chemical mechanical polishing process for the formation of self-aligned gate structures surrounding an electron emission tip for use in field emission displays in which the emission tip is i) optionally sharpened through oxidation, ii) deposited with a conformal insulating material, iii) deposited with a flowable insulating material, which is reflowed below the level of the tip, iv) optionally deposited with another insulating material, v) deposited with a conductive material layer, and vi) optionally, deposited with a buffering material, vii) planarized with a chemical mechanical planarization (CMP) step, to expose the conformal insulating layer, viii) wet etched to remove the insulating material and thereby expose the emission tip, afterwhich ix) the emitter tip may be coated with a material having a lower work function than silicon.
Inventors
- 👤 Trung T. Doan
- 👤 J. Brett Rolfson
- 👤 Tyler A. Lowrey
- 👤 David A. Cathey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 10:19
CPC Classifications
H; H01; H01J; H01J9/00; H01J9/02; H01J9/022; H01J9/025; H10; H10P; H10P95/00; H10P95/06; H10P95/062; H01J2201/00; H01J2201/30; H01J2201/304; H01J2201/30403; H01J2201/30426; H01J2201/319; H01J2209/00; H01J2209/02; H01J2209/022; H01J2209/0223; H01J2209/0226
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
75 words
A process for the formation of self-aligned gate structures around an electron emitter, said process comprising the following steps: planarizing at least one electron emitter overlaid with oxide and polysilicon layers, wherein at least one of said layers comprises at least one of a conformal material and a non-conformal material, said planarizing involving chemical mechanical means; and selectively removing said oxide and said polysilicon layers, thereby exposing at least a portion of said electron emitter.
Claim 2
Dependent Claim
75 words
A process for the formation of self-aligned gate structures around an electron emitter, said process comprising the following steps: planarizing at least one electron emitter overlaid with oxide and polysilicon layers, wherein at least one of said layers comprises at least one of a conformal material and a non-conformal material, said planarizing involving chemical mechanical means; and selectively removing said oxide and said polysilicon layers, thereby exposing at least a portion of said electron emitter.
Claim 3
Dependent Claim
22 words
The process according to claim 1, wherein a buffer layer is disposed over said polysilicon layer, said buffer layer comprising silicon nitride.
Claim 4
Dependent Claim
47 words
The process according to claim 2, wherein said chemical mechanical means comprises a wetted polishing surface against which to rotate said overlaid electron emitter under controlled chemical slurry, pressure, and temperature conditions, said chemical slurry comprising at least one of alumina and silica, and a chemical etchant.
Claim 5
Dependent Claim
18 words
The process according to claim 1, wherein said oxide and said polysilicon layers are selectively removed by etching.
Claim 6
Dependent Claim
20 words
The process according to claim 4, wherein said electron emitter comprises a cold cathode, said cold cathode having a tip.
Claim 7
Dependent Claim
16 words
The process according to claim 5, further comprising the step of: sharpening said tip by oxidation.
Claim 8
Dependent Claim
17 words
The process according to claim 6, further comprising the step of: coating said tip with a silicide.
Claim 9
Dependent Claim
87 words
A process for the formation of a grid structure around an electron emitter, said process comprising the following steps: forming at least one cathode on a substrate; forming at least one insulating layer superjacent said cathode; depositing at least one conductive material layer superjacent said insulating layer; planarizing said layers by chemical mechanical planarization (CMP); and removing said layers to expose at least a portion of said cathode, wherein at least one of said layers comprises at least one of a conformal material and a non-conformal material.
Claim 10
Dependent Claim
87 words
A process for the formation of a grid structure around an electron emitter, said process comprising the following steps: forming at least one cathode on a substrate; forming at least one insulating layer superjacent said cathode; depositing at least one conductive material layer superjacent said insulating layer; planarizing said layers by chemical mechanical planarization (CMP); and removing said layers to expose at least a portion of said cathode, wherein at least one of said layers comprises at least one of a conformal material and a non-conformal material.
Claim 11
Dependent Claim
19 words
The process according to claim 8, wherein said cathode is an electron emitter, said electron emitter having a tip.
Claim 12
Dependent Claim
24 words
The process according to claim 8, further comprising the step of: depositing a buffer material prior to subjecting the cathode to chemical mechanical planarization.
Claim 13
Dependent Claim
14 words
The process according to claim 8, wherein said insulating layer is grown through oxidation.
Claim 14
Dependent Claim
23 words
The process according to claim 8, wherein said removing further comprises the step of: etching said insulating layer thereby defining a gate structure.
Claim 15
Dependent Claim
19 words
The process according to claim 8, wherein said insulating layer is selectively etchable with respect to said conductive layer.
Claim 16
Dependent Claim
20 words
The process according to claim 8, wherein said substrate comprises at least one of polysilicon, doped polysilicon, and a silicide.
Claim 17
Dependent Claim
22 words
The process according to claim 8, wherein said insulating layer comprises at least one of silicon dioxide, silicon nitride, and silicon oxynitride.
Claim 18
Dependent Claim
133 words
A process for the formation of self-aligned gate structures around an electron emitting tip, said process comprising the following steps: forming at least one cathode on a substrate, said cathode having an emitter tip; forming a first layer superjacent said emitter tip; depositing a second layer superjacent said first layer, wherein at least one of said first and second layer comprise at least one of a conformal material and a non-conformal material; polishing said substrate by chemical mechanical means to expose at least a portion of said second layer, wherein said chemical mechanical means comprises an abrasive compound in a polishing slurry; and selectively removing said layers to expose the emitter tip, wherein said first layer is selectively removed by etching, said first layer being selectively etchable with respect to said second layer.
Claim 19
Dependent Claim
133 words
A process for the formation of self-aligned gate structures around an electron emitting tip, said process comprising the following steps: forming at least one cathode on a substrate, said cathode having an emitter tip; forming a first layer superjacent said emitter tip; depositing a second layer superjacent said first layer, wherein at least one of said first and second layer comprise at least one of a conformal material and a non-conformal material; polishing said substrate by chemical mechanical means to expose at least a portion of said second layer, wherein said chemical mechanical means comprises an abrasive compound in a polishing slurry; and selectively removing said layers to expose the emitter tip, wherein said first layer is selectively removed by etching, said first layer being selectively etchable with respect to said second layer.
Claim 20
Dependent Claim
20 words
The process according to claim 16, wherein said first layer comprises an insulator and said second layer comprises a conductor.
Claim 21
Dependent Claim
22 words
The process according to claim 17, wherein said insulating layer comprises at least one of silicon dioxide, silicon nitride, and silicon oxynitride.
Claim 22
Dependent Claim
19 words
The process according to claim 18, wherein said emitter tip is disposed in an array of similar emitter tips.
Claim 23
Dependent Claim
16 words
The process according to claim 19, wherein said array is disposed in a flat panel display.
References Cited (Backward Citations)
US3755704A
Cited
US3665241A
Cited
US3812559A
Cited
US3875442A
Cited
US3998678A
Cited
US3970887A
Cited
US3921022A
Cited
JPS56160740A
Cited
US4666553A
Cited
US4671851A
Cited
US4746629A
Cited
US4857799A
Cited
US5070282A
Cited
US4943343A
Cited
US5143820A
Cited
US4964946A
Cited
US5036015A
Cited
US5055158A
Cited
US5266530A
Cited
US5229331A
Cited
US5186670A
Cited
US5259799A
Cited
US5232549A
Cited
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