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US5100355A
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US
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Microminiature tapered all-metal structures
Assignee: STANFORD UNIVERSITY OTL LLC
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Filing: 1991-06-28
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Granted: 1992-03-31
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Expires: 2011-06-28
Abstract
Abstract In a structure comprising an ultra-sharp silicon tip coated with a layer of material, the silicon is removed from the structure. The remaining material is utilized as a mold. Metal deposited in the mold replicates the original silicone tip. In this way, ultra-sharp all-metal tips suitable, for example, as field-emitter sources are provided.
Inventors
- 👤 Robert B. Marcus
- 👤 Tirunelveli S. Ravi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 12:01
CPC Classifications
G; G01; G01Q; G01Q70/00; G01Q70/08; G01Q70/10; B; B82; B82Y; B82Y35/00; G01Q70/14; G01Q70/16; H; H01; H01J; H01J9/00; H01J9/02; H01J9/022; H01J9/025
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
101 words
A method of making a microminiature tapered all-metal structure, said method comprising the steps of: forming in a top surface of a silicon substrate a tapered silicon protuberance which terminates in an apex whose radius of curvature is less than 10 nanometers, covering the entire surface of said protuberance with a layer of material, removing the entirety of said silicon while leaving said layer of material substantially intact to serve as a mold whose contour is substantially identical to that of said tapered silicon protuberance, depositing a metal in said mold, and removing the layer of material from said deposited metal.
Claim 2
Independent Claim
101 words
A method of making a microminiature tapered all-metal structure, said method comprising the steps of: forming in a top surface of a silicon substrate a tapered silicon protuberance which terminates in an apex whose radius of curvature is less than 10 nanometers, covering the entire surface of said protuberance with a layer of material, removing the entirety of said silicon while leaving said layer of material substantially intact to serve as a mold whose contour is substantially identical to that of said tapered silicon protuberance, depositing a metal in said mold, and removing the layer of material from said deposited metal.
Claim 3
Dependent Claim
14 words
A method as in claim 1 wherein siad layer of material comprises silicon dioxide.
Claim 4
Dependent Claim
14 words
A method as in claim 1 wherein said layer of material comprises silicon nitride.
Claim 5
Dependent Claim
20 words
A method as in claim 1 wherein said metal is selected from the group consisting of tungsten, molybdenum and aluminum.
Claim 6
Dependent Claim
19 words
A method as in claim 4 wherein said layer of material is at least approximately 3500 Angstrom units thick.
Claim 7
Dependent Claim
63 words
A method as in claim 5 wherein the step of removing said silicon comprises initially mechanically abrading the bottom surface of said silicon substrate, etching the bottom surface of said abraded silicon substrate in a wet etching step in a mixture of hydrofluric, nitric and acetic acids, and then removing the remainder of said silicon in a wet etching step utilizing potassium hydroxide.
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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) | 1995-03-31 | 1995-09-30 | 1996-03-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-03-31 | 1999-09-30 | 2000-03-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-03-31 | 2003-09-30 | 2004-03-31 | $7700.00 | Window Closed / Lapsed |