US6117344A
Expired / Lapsed
US
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Method for manufacturing low work function surfaces
Assignee: WheelTug PLC
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Filing: 1998-03-20
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Granted: 2000-09-12
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Expires: 2018-03-20
Abstract
Abstract Methods for fabricating nano-structured surfaces having geometries in which the passage of elementary particles through a potential barrier is enhanced are described. The methods use combinations of electron beam lithography, lift-off, and rolling, imprinting or stamping processes.
Inventors
- 👤 Isaiah Watas Cox
- 👤 Avto Tavkhelidze
- 👤 Jonathan Sidney Edelson
- 👤 Stuart Harbron
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 04:08
CPC Classifications
B; B82; B82Y; B82Y10/00; G; G03; G03F; G03F7/00; G03F7/0002; B82Y40/00; H; H01; H01J; H01J1/00; H01J1/02; H01J1/30; H01J45/00; H01J9/00; H01J9/02; H01J9/022; G03F7/20; G03F7/2051; G03F7/2059; G03F7/2065
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
189 words
A process for making an elementary particle emitting surface, comprising the steps of: a. positioning into the path of a particle beam a layer of material whose molecules are modified when exposed to said particle beam, b. directionally focusing said particle beam on said material and exposing a pattern of molecules to the beam such that the modified molecules and the unmodified molecules of said material form a pattern that comprises an indented cross-section comprising protruding portions separated by spaces, and further wherein the depths of indents in said indented cross-section is given by the relationship nλ+λ/4, where λ is the de Broglie wavelength for said elementary particles and where n is 0 or a positive integer selected such that the geometric shape of said indented cross-section causes de Broglie interference between said elementary particles, c. developing said material to remove either said modified molecules or said unmodified molecules, whereby molecules not removed by said developing form at least said protruding portions of said indented cross-section, d. transferring said pattern of said indented cross-section to a surface of a substrate whereby said indented cross-section is created on said substrate.
Claim 2
Dependent Claim
189 words
A process for making an elementary particle emitting surface, comprising the steps of: a. positioning into the path of a particle beam a layer of material whose molecules are modified when exposed to said particle beam, b. directionally focusing said particle beam on said material and exposing a pattern of molecules to the beam such that the modified molecules and the unmodified molecules of said material form a pattern that comprises an indented cross-section comprising protruding portions separated by spaces, and further wherein the depths of indents in said indented cross-section is given by the relationship nλ+λ/4, where λ is the de Broglie wavelength for said elementary particles and where n is 0 or a positive integer selected such that the geometric shape of said indented cross-section causes de Broglie interference between said elementary particles, c. developing said material to remove either said modified molecules or said unmodified molecules, whereby molecules not removed by said developing form at least said protruding portions of said indented cross-section, d. transferring said pattern of said indented cross-section to a surface of a substrate whereby said indented cross-section is created on said substrate.
Claim 3
Dependent Claim
13 words
The process of claim 1 wherein said particle beam is an electron beam.
Claim 4
Dependent Claim
26 words
The process of claim 2 further comprising a step of mounting said material on said substrate prior to exposure of said material to said electron beam.
Claim 5
Dependent Claim
31 words
The process of claim 3 wherein said material comprises a polymer, and further wherein the step of mounting said polymer on said substrate comprises spin coating said polymer onto said substance.
Claim 6
Dependent Claim
25 words
The process of claim 4 wherein the step of transferring said pattern comprises transferring said pattern to a surface of said substrate beneath said polymer.
Claim 7
Dependent Claim
20 words
The process of claim 5 wherein the step of transferring said pattern to said substrate beneath said polymer comprises etching.
Claim 8
Dependent Claim
25 words
The process of claim 6 wherein said etching comprises an etching process selected from the group consisting of: chemical etching, isotropic etching, and anisotropic etching.
Claim 9
Dependent Claim
53 words
The process of claim 2 further comprising the step of mounting said material on said substrate prior to exposure of said material to said electron beam, wherein, after said exposure and said developing, said substrate is covered by said material except where said molecules of said material have been removed by said developing.
Claim 10
Dependent Claim
52 words
The process of claim 8 further comprising the step of depositing a second material on said material after developing said material, but prior to transferring said pattern, such that said second material covers at least the areas of said substrate which are not covered by said protruding portions of said indented cross-section.
Claim 11
Dependent Claim
65 words
The process of claim 9 wherein the step of transferring said pattern to said substrate comprises removing said protruding portions of said indented cross-section and the parts of said second material which lie above said protruding portions of said indented cross-section, whereby some of the second material remains in a pattern of the shape of the spaces between said protruding portions of said indented cross-section.
Claim 12
Dependent Claim
26 words
The process of claim 10 wherein said removing comprises a process selected from the group consisting of: chemical etching, isotropic etching, anisotropic etching, evaporating and dissolving.
Claim 13
Dependent Claim
14 words
The process of claim 1 wherein said particle beam is an oxygen atom beam.
Claim 14
Dependent Claim
25 words
The process of claim 12 wherein the step of transferring said pattern to said substrate is done by isotropically oxidizing said surface of said substrate.
Claim 15
Dependent Claim
58 words
The process of claim 1 additionally comprising the steps of: a. providing a second substrate coated with a polymer coat, b. pressing said substrate having said indented cross-section against said polymer coat on said second substrate, c. etching said second substrate using a constant rate etchant to yield a predetermined pattern on the surface of said second substrate.
Claim 16
Dependent Claim
57 words
The process of claim 1 additionally comprising the steps of: a. bringing said substrate having said indented cross-section into contact with a second substrate, b. applying pressure to said substrate having said indented cross-section, to cause said second substrate to have a surface having impressions corresponding to the protruding portions of said substrate having said indented cross-section.
Claim 17
Dependent Claim
37 words
The process of claim 15, wherein said second substrate has a melting temperature lower than said substrate having said indented cross-section, and additionally comprising the step of heating said second substrate, whereby said second substrate is softened.
Claim 18
Dependent Claim
30 words
The process of claim 15 additionally comprising the step of treating said second substrate with a hardening agent after said impressions have been formed, whereby said second substrate is hardened.
Claim 19
Dependent Claim
60 words
A process for preparing an elementary particle emitting surface having a geometrical shape for causing de Broglie interference between said elementary particles, comprising the steps of: a. providing a metal substrate, b. etching said metal substrate by oxygen atom beam etching means to give an oxide pattern, c. dissolving said oxide to give a substrate having said predetermined lattice pattern.
Claim 20
Dependent Claim
60 words
A process for preparing an elementary particle emitting surface having a geometrical shape for causing de Broglie interference between said elementary particles, comprising the steps of: a. providing a metal substrate, b. etching said metal substrate by oxygen atom beam etching means to give an oxide pattern, c. dissolving said oxide to give a substrate having said predetermined lattice pattern.
Claim 21
Dependent Claim
76 words
A process for preparing an elementary particle emitting surface having a geometrical shape for causing de Broglie interference between said elementary particles, comprising the steps of: a. providing a metal substrate, b. etching said metal substrate by oxygen atom beam etching means to give an oxide pattern, c. subjecting the substrate to isotropic oxidation, yielding a flat surface having indented oxide regions, which provide a potential energy barrier causing de Broglie interference between said elementary particles.
Claim 22
Dependent Claim
76 words
A process for preparing an elementary particle emitting surface having a geometrical shape for causing de Broglie interference between said elementary particles, comprising the steps of: a. providing a metal substrate, b. etching said metal substrate by oxygen atom beam etching means to give an oxide pattern, c. subjecting the substrate to isotropic oxidation, yielding a flat surface having indented oxide regions, which provide a potential energy barrier causing de Broglie interference between said elementary particles.
Claim 23
Dependent Claim
45 words
The process of claim 8, further wherein the step of transferring said pattern to said substrate comprises etching away said material and said substrate, wherein said etching etches deeper into said substrate in areas which are not covered by said protruding portions of said indents.
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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) | 2003-09-12 | 2004-03-13 | 2004-09-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-09-12 | 2008-03-13 | 2008-09-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-09-12 | 2012-03-13 | 2012-09-12 | $7700.00 | Window Closed / Lapsed |