Patent US6002202A successfully refreshed from Google Patents.
US6002202A
Expired / Lapsed
US
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Rigid thin windows for vacuum applications
Assignee: University of California
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Filing: 1996-07-19
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Granted: 1999-12-14
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Expires: 2016-07-19
Abstract
Abstract A thin window that stands off atmospheric pressure is fabricated using photolithographic and wet chemical etching techniques and comprises at least two layers: an etch stop layer and a protective barrier layer. The window structure also comprises a series of support ribs running the width of the window. The windows are typically made of boron-doped silicon and silicon nitride and are useful in instruments such as electron beam guns and x-ray detectors. In an electron beam gun, the window does not impede the electrons and has demonstrated outstanding gun performance and survivability during the gun tube manufacturing process.
Inventors
- 👤 Glenn Allyn Meyer
- 👤 Dino R. Ciarlo
- 👤 Booth Richard Myers
- 👤 Hao-Lin Chen
- 👤 George Wakalopulos
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 07:09
CPC Classifications
B; B44; B44C; B44C1/00; B44C1/22; H; H01; H01J; H01J33/00; H01J33/02; H01J33/04
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
95 words
A method of making a thin window for vacuum applications, comprising: selecting a substrate comprising silicon; forming an etch stop layer on one side of the substrate; forming a continuous protective barrier layer on the etch stop layer of a material different from the etch stop layer; removing portions of the silicon substrate such that a bilayer window comprising the etch stop layer and protective barrier layer is formed, and such that a plurality of support ribs comprising silicon are formed in contact with the etch stop layer and running the width of the window.
Claim 2
Independent Claim
95 words
A method of making a thin window for vacuum applications, comprising: selecting a substrate comprising silicon; forming an etch stop layer on one side of the substrate; forming a continuous protective barrier layer on the etch stop layer of a material different from the etch stop layer; removing portions of the silicon substrate such that a bilayer window comprising the etch stop layer and protective barrier layer is formed, and such that a plurality of support ribs comprising silicon are formed in contact with the etch stop layer and running the width of the window.
Claim 3
Dependent Claim
29 words
A method as recited in claim 1, wherein the etch stop layer comprises a material selected from the group consisting of doped silicon, and conductive carbides, nitrides, and borides.
Claim 4
Dependent Claim
57 words
A method as recited in claim 2, wherein the etch stop layer comprises a material selected from the group consisting of B 4 C, HfC, NbC, TiC, ZrC, SiC, AlN, HfN, NbN, Nb 2 N, TiN, TaN, Ta 2 N, ZrN, HfB 2 , NbB 2 , TaB 2 , TiB 2 , and ZrB 2 .
Claim 5
Dependent Claim
27 words
A method as recited in claim 2, wherein the etch stop layer comprises a material selected from the group consisting of doped silicon and doped silicon carbide.
Claim 6
Dependent Claim
24 words
A method as recited in claim 4, wherein at least one dopant is selected from the group consisting of boron, phosphorous, antimony, and arsenic.
Claim 7
Dependent Claim
30 words
A method as recited in claim 4, wherein the etch stop layer comprises at least two dopants selected from the group consisting of boron, phosphorous, antimony, arsenic, tin, and germanium.
Claim 8
Dependent Claim
32 words
A method as recited in claim 2, wherein the etch stop layer comprises a material selected from the group consisting of boron doped silicon and boron doped germanium strain compensated epitaxial silicon.
Claim 9
Dependent Claim
18 words
A method as recited in claim 1, further comprising forming the etch stop layer by a diffusion process.
Claim 10
Dependent Claim
19 words
A method as recited in claim 1, further comprising forming the etch stop layer by an epitaxial deposition process.
Claim 11
Dependent Claim
26 words
A method as recited in claim 1, wherein the protective barrier layer comprises a material selected from the group consisting of borides, carbides, nitrides, and oxides.
Claim 12
Dependent Claim
76 words
A method as recited in claim 10, wherein the protective barrier layer comprises a material selected from the group consisting of B 4 C, HfC, NbC, doped SiC, TiC, ZrC, Si 3 N 4 , AlN, HfN, NbN, Nb 2 N, TiN, TaN, Ta 2 N, ZrN, HfB 2 , NbB 2 , TaB 2 , TiB 2 , ZrB 2 , Al 2 O 3 , ZrO 2 , and Ta 2 O 5 .
Claim 13
Dependent Claim
15 words
A method as recited in claim 10, wherein the protective barrier layer comprises silicon nitride.
Claim 14
Dependent Claim
37 words
A method as recited in claim 12, wherein the protective barrier layer comprises a low stress silicon nitride film having a tensile stress of about -50 to -500 MPa (5×10 8 to 5×10 9 dynes/cm 2 ).
Claim 15
Dependent Claim
36 words
A method as recited in claim 1, further comprising forming a third layer on the protective barrier layer, wherein the third layer comprises a material selected from the group consisting of carbides, nitrides, borides, and oxides.
Claim 16
Dependent Claim
27 words
A method as recited in claim 1, wherein removing portions of the silicon substrate is carried out by a photolithographic process followed by wet chemical anisotropic etching.
Claim 17
Dependent Claim
23 words
A method as recited in claim 15, wherein the wet etching is carried out using a potassium hydroxide/deionized water solution with isopropyl alcohol.
Claim 18
Dependent Claim
99 words
A thin window for vacuum applications, comprising: a first layer effective as an etch stop in silicon etching, comprising a material selected from the group consisting of doped silicon, and conductive carbides, nitrides, and borides; a continuous protective barrier layer formed on the first layer, comprising a material different from the etch stop layer and selected from the group consisting of borides, carbides, nitrides, and oxides, wherein the first layer and barrier layer form a window; and a plurality of support ribs comprising silicon formed in contact with the first layer and running the width of the bilayer window.
Claim 19
Dependent Claim
99 words
A thin window for vacuum applications, comprising: a first layer effective as an etch stop in silicon etching, comprising a material selected from the group consisting of doped silicon, and conductive carbides, nitrides, and borides; a continuous protective barrier layer formed on the first layer, comprising a material different from the etch stop layer and selected from the group consisting of borides, carbides, nitrides, and oxides, wherein the first layer and barrier layer form a window; and a plurality of support ribs comprising silicon formed in contact with the first layer and running the width of the bilayer window.
Claim 20
Dependent Claim
18 words
A window as recited in claim 17, further comprising a silicon support frame connected to the support ribs.
Claim 21
Dependent Claim
12 words
A window as recited in claim 17, wherein the ribs are tapered.
Claim 22
Dependent Claim
16 words
A window as recited in claim 17, wherein the ribs are perpendicular to the first layer.
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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) | 2002-12-13 | 2003-06-14 | 2003-12-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-12-13 | 2007-06-14 | 2007-12-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-12-13 | 2011-06-14 | 2011-12-14 | $7700.00 | Window Closed / Lapsed |