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US4968382A
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: 1990-11-06
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Expires: 2010-01-12
Abstract
Abstract In the production of micron-size pyramid emitters for field emission devices, very sharp emitter points are achieved by providing a layer of suitable metal, metal compound or semiconductor, forming masking pads over the required emitter positions, etching the layer so that column-like structures are formed beneath the pads, removing the pads, and then subjecting the columns to dry etching, such as plasma etching, reactive ion etching, ion beam milling or reactive ion beam milling. The dry etching process shapes the columns into pyramids with a tip size of the order of 0.03 microns.
Inventors
- 👤 Susan E. Jacobson
- 👤 Rosemary A. Lee
- 👤 Helen A. Williams
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 09:22
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: 14
Claim 1
Independent Claim
55 words
A method of forming an electrode, the method comprising providing a layer of electrically-conductive material; forming a masking pad on said layer in the required position for said electrode; etching the layer so that an electrode structure is formed beneath the pad; removing the pad; and dry etching the structure to produce a sharply-pointed electrode.
Claim 2
Independent Claim
55 words
A method of forming an electrode, the method comprising providing a layer of electrically-conductive material; forming a masking pad on said layer in the required position for said electrode; etching the layer so that an electrode structure is formed beneath the pad; removing the pad; and dry etching the structure to produce a sharply-pointed electrode.
Claim 3
Dependent Claim
25 words
A method as claimed in claim 1, wherein the etching of the layer to form an electrode structure is effected by a wet etching process.
Claim 4
Dependent Claim
25 words
A method as claimed in claim 1, wherein the etching of the layer to form an electrode structure is effected by a dry etching process.
Claim 5
Dependent Claim
36 words
A method as claimed in claim 3, wherein the etching of the layer and the dry etching of the structure are effected in a substantially continuous process; and wherein the pad is removed by said process.
Claim 6
Dependent Claim
27 words
A method as claimed in claim 1, wherein the dry etching is effected by plasma etching, reactive ion etching, ion beam milling, or reactive ion beam milling.
Claim 7
Dependent Claim
35 words
A method as claimed in claim 3, wherein the etching of the layer is effected by a plasma etching process and the dry etching of the structure is effected by a reactive ion etching process.
Claim 8
Dependent Claim
23 words
A method as claimed in claim 6, wherein the plasma etching process is carried out in SF 6 /Cl 2 /O 2 .
Claim 9
Dependent Claim
22 words
A method as claimed in claim 6, wherein the reactive ion etching process is carried out in SF 6 /N 2 .
Claim 10
Dependent Claim
17 words
A method as claimed in claim 1, wherein the electrode structure formed beneath the pad is tapered.
Claim 11
Dependent Claim
20 words
A method as claimed in claim 1, wherein the electrode structure formed beneath the pad is a substantially parallel-sided column.
Claim 12
Dependent Claim
21 words
A method as claimed in claim 1, wherein the layer is formed of a semiconductor, a metal or a metal compound.
Claim 13
Dependent Claim
21 words
A method as claimed in claim 11, wherein the layer is formed of silicon, niobium, molybdenum, gold, nickel tungsten or rhodium.
Claim 14
Dependent Claim
19 words
A method as claimed in claim 12, wherein the layer is formed of single crystal nickel, tungsten or rhodium.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-11-05 | 1994-05-07 | 1994-11-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-11-05 | 1998-05-07 | 1998-11-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-11-05 | 2002-05-07 | 2002-11-06 | $7700.00 | Window Closed / Lapsed |