US5259799A
Expired / Lapsed
US
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Method to form self-aligned gate structures and focus rings
Assignee: Micron Technology Inc
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Filing: 1992-11-17
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Granted: 1993-11-09
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Expires: 2012-11-17
Abstract
Abstract A selective etching and chemical mechanical planarization process for the formation of self-aligned gate and focus ring 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 first conformal layer, iii) deposited with a conductive material layer, iv) deposited with a second conformal insulating layer, v) deposited with a focus electrode ring material layer, vi) optionally deposited with a buffering material, vii) planarized with a chemical mechanical planarization (CMP) step, to expose a portion of the second conformal layer, viii) etched to form a self-aligned gate and focus ring, and thereby expose the emitter tip, afterwhich xi) the emitter tip may be coated with a low work function material.
Inventors
- 👤 Trung T. Doan
- 👤 Tyler A. Lowrey
- 👤 David A. Cathey
- 👤 J. Brett Rolfson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:42
CPC Classifications
H; H01; H01J; H01J9/00; H01J9/02; H01J9/022; H01J9/025; H01J2209/00; H01J2209/02; H01J2209/022; H01J2209/0223; H01J2209/0226; H01J2329/00
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
58 words
A process for the formation of self-aligned gate and focus ring structures around an electron emitter, said process comprising the following steps: planarizing at least one electron emitter overlaid with insulating and conductive layers, said planarizing involving chemical mechanical means; and selectively removing said insulating and conductive layers, thereby exposing at least a portion of said electron emitter.
Claim 2
Dependent Claim
58 words
A process for the formation of self-aligned gate and focus ring structures around an electron emitter, said process comprising the following steps: planarizing at least one electron emitter overlaid with insulating and conductive layers, said planarizing involving chemical mechanical means; and selectively removing said insulating and conductive layers, thereby exposing at least a portion of said electron emitter.
Claim 3
Dependent Claim
31 words
The process according to claim 1, wherein said chemical mechanical means comprises rotation of said overlaid electron emitter against a wetted polishing surface under controlled chemical slurry, pressure, and temperature conditions.
Claim 4
Dependent Claim
14 words
The process according to claim 2, wherein said chemical slurry comprises a polishing agent.
Claim 5
Dependent Claim
14 words
The process according to claim 3, wherein said chemical slurry further comprises chemical etchants.
Claim 6
Dependent Claim
17 words
The process according to claim 4, wherein said insulating and conductive layers are selectively removed by etching.
Claim 7
Dependent Claim
13 words
The process according to claim 5, wherein said electron emitter comprises a cathode.
Claim 8
Dependent Claim
12 words
The process according to claim 6, wherein said cathode has a tip.
Claim 9
Dependent Claim
19 words
The process according to claim 7, further comprising the step of: sharpening said tip of said cathode by oxidation.
Claim 10
Dependent Claim
23 words
The process according to claim 8, further comprising the step of: coating said tip of said cathode with a low work function material.
Claim 11
Dependent Claim
68 words
A process for the formation of multiple grid structures around an electron emitter, said process comprising the following steps: forming at least one cathode on a substrate; forming at least two insulating layers superjacent said cathode; depositing at least two conductive material layers superjacent said insulating layers; planarizing said layers by chemical mechanical planarization (CMP); and removing said layers to expose at least a portion of said cathode.
Claim 12
Dependent Claim
68 words
A process for the formation of multiple grid structures around an electron emitter, said process comprising the following steps: forming at least one cathode on a substrate; forming at least two insulating layers superjacent said cathode; depositing at least two conductive material layers superjacent said insulating layers; planarizing said layers by chemical mechanical planarization (CMP); and removing said layers to expose at least a portion of said cathode.
Claim 13
Dependent Claim
19 words
The process according to claim 10, wherein said cathode is an electron emitter, said electron emitter having a tip.
Claim 14
Dependent Claim
24 words
The process according to claim 11, further comprising the step of: depositing a buffer material prior to subjecting the cathode to chemical mechanical planarization.
Claim 15
Dependent Claim
18 words
The process according to claim 12, wherein at least one of said insulating layers is growth through oxidation.
Claim 16
Dependent Claim
28 words
The process according to claim 13, wherein said removing further comprises the step of: etching said at least two insulating layers thereby defining gate and focus ring structures.
Claim 17
Dependent Claim
19 words
The process according to claim 14, wherein said insulating layers are selectively etchable with respect to said conductive layers.
Claim 18
Dependent Claim
20 words
The process according to claim 15, wherein said substrate comprises at least one of polysilicon, doped polysilicon, and silicized silicon.
Claim 19
Dependent Claim
22 words
The process according to claim 16, wherein said insulating layers comprise at least one of silicon dioxide, silicon nitride, and silicon oxynitride.
Claim 20
Dependent Claim
106 words
A process for the formation of self-aligned gate and focus ring 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 insulating layer superjacent said emitter tip; depositing a conductive material layer superjacent said first insulating layer; depositing a second insulating layer superjacent said conductive material layer; depositing a focus electrode material layer superjacent said second insulating layer; polishing said substrate by chemical mechanical planarization (CMP) to expose at least a portion of said conductive material layer; and selectively removing said layers to expose the emitter tip.
Claim 21
Dependent Claim
106 words
A process for the formation of self-aligned gate and focus ring 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 insulating layer superjacent said emitter tip; depositing a conductive material layer superjacent said first insulating layer; depositing a second insulating layer superjacent said conductive material layer; depositing a focus electrode material layer superjacent said second insulating layer; polishing said substrate by chemical mechanical planarization (CMP) to expose at least a portion of said conductive material layer; and selectively removing said layers to expose the emitter tip.
Claim 22
Dependent Claim
36 words
The process according to claim 18, wherein said first and second insulating layers are selectively removed by etching, said insulating layers being selectively etchable with respect to said conductive material layer and said focus electrode layer.
Claim 23
Dependent Claim
23 words
The process according to claim 19, wherein the chemical mechanical planarization (CMP) step is performed with an abrasive compound in a polishing slurry.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-11-08 | 1997-05-10 | 1997-11-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-11-08 | 2001-05-10 | 2001-11-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-11-08 | 2005-05-10 | 2005-11-09 | $7700.00 | Window Closed / Lapsed |