US5147501A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electronic devices
Assignee: The General Electric Company PLC
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Filing: 1990-01-12
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Granted: 1992-09-15
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Expires: 2010-01-12
Abstract
Abstract In the production of micron-size pyramid emitters for field emission devices, a first layer of electrically-conductive material, such as single crystal silicon or metal, is etched to form column-like structures each of which tapers from each end of the column towards an intermediate portion along its length. A second conductive layer is formed in contact with the free ends of the columns, and etching of the columns is then resumed until the intermediate portion of each column is etched through, leaving a pair of pyramid emitters pointing towards one another and supported by the respective conductive layer.
Inventors
- 👤 Neil A. Cade
- 👤 Rosemary A. Lee
- 👤 Chandrakant Patel
- 👤 Helen A. Williams
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 12:09
CPC Classifications
H; H01; H01J; H01J9/00; H01J9/02; H01J9/022; H01J9/025; H01J1/00; H01J1/02; H01J1/30; H01J1/304; H01J1/3042
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
133 words
A method of forming an electron emission device, the method comprising the steps of: providing a first layer of electrically-conductive material; forming from said first layer a column-like structure having a first end integral with said first layer and a second end, said structure having a first portion tapering from said first end towards an intermediate region of the structure and a second portion tapering from said second end towards said intermediate region; said second end of said structure being attached to a second electrically-conductive layer spaced from said first layer; and removing part of the structure at said intermediate region to separate said first and second portions from each other, whereby two tapered bodies are provided with their sharp ends substantially aligned and closely spaced, to form respective electrodes of the device.
Claim 2
Independent Claim
133 words
A method of forming an electron emission device, the method comprising the steps of: providing a first layer of electrically-conductive material; forming from said first layer a column-like structure having a first end integral with said first layer and a second end, said structure having a first portion tapering from said first end towards an intermediate region of the structure and a second portion tapering from said second end towards said intermediate region; said second end of said structure being attached to a second electrically-conductive layer spaced from said first layer; and removing part of the structure at said intermediate region to separate said first and second portions from each other, whereby two tapered bodies are provided with their sharp ends substantially aligned and closely spaced, to form respective electrodes of the device.
Claim 3
Dependent Claim
45 words
A method as claimed in claim 1, wherein the formation of the column-like structure is effected by first forming a substantially straight-sided pillar from said first layer and subsequently etching the sides of the pillar and the first layer therebeneath to form the tapered structure.
Claim 4
Dependent Claim
35 words
A method as claimed in claim 2, wherein the second electrically-conductive layer is formed in contact with said structure after the etching of the sides of the pillar and the first layer has been effected.
Claim 5
Dependent Claim
29 words
A method as claimed in claim 2, wherein the second electrically-conductive layer is formed in contact with said first layer before formation of the pillar from said first layer.
Claim 6
Dependent Claim
28 words
A method as claimed in claim 2, wherein the column-like structure is formed by subjecting said pillar and said first layer therebeneath to an anisotropic wet etching process.
Claim 7
Dependent Claim
17 words
A method as claimed in claim 1, wherein said first layer is formed of single crystal silicon.
Claim 8
Dependent Claim
17 words
A method as claimed in claim 1, wherein said first layer is formed of single crystal metal.
Claim 9
Dependent Claim
12 words
A method as claimed in claim 7, wherein said metal is tungsten.
Claim 10
Dependent Claim
44 words
A method as claimed in claim 1, wherein the step of removing part of the structure at said intermediate portion is monitored by checking for abrupt change in electrical resistance between said first and second layers occurring when said first and second portions separate.
Claim 11
Dependent Claim
36 words
A method as claimed in claim 3, further comprising the steps of encircling the structure with a layer of support material; depositing said second electrically-conductive layer on the support material; and thereafter removing the support material.
References Cited (Backward Citations)
GB1226627A
Cited
US3789471A
Cited
GB1374930A
Cited
US4522682A
Cited
WO1988006345A1
Cited
US4983878A
Cited
US4973378A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-09-15 | 1996-03-16 | 1996-09-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-09-15 | 2000-03-16 | 2000-09-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-09-15 | 2004-03-16 | 2004-09-15 | $7700.00 | Window Closed / Lapsed |