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US4344816A Expired / Lapsed US ⏱️ 0.0 years remaining

Selectively etched bodies

Assignee: AT&T Inc
•
Filing: 1980-12-19
•
Granted: 1982-08-17
•
Expires: 2000-12-19
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Abstract

Abstract Bodies having conical structures with dimensions on the order of the wavelength of visible light are prepared by a specific process. This process involves the formation of a mask by depositing a material that forms the mask onto the body to be etched and choosing the mask material so that it does not substantially wet the surface of the body. The mask thus fabricated has hill-type formations where the spacings between these formations are of the order of the wavelength of visible light. An etchant that etches the mask at a specific rate relative to the underlying body is then used to perform the etching procedure. Exemplary bodies produced by the procedure include tungsten textured bodies that exhibit light emissivities significantly higher than those possessed by the corresponding untreated tungsten material.

Inventors

  • 👤 Harold G. Craighead
  • 👤 Richard E. Howard
  • 👤 Donald M. Tennant

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-25 19:56
CPC Classifications
C; C23; C23F; C23F4/00; Y; Y10; Y10S; Y10S428/00; Y10S428/922; Y10S428/9265; Y10S428/929; Y10T; Y10T428/00; Y10T428/12; Y10T428/12431

Claims Analysis

Total Claims: 13
Claim 1
Independent Claim 71 words
A process for producing an article comprising the steps of forming a mask on the surface of a substrate and etching said substrate by anisotropic etching characterized in that said mask is formed by depositing onto said substrate a material that does not substantially wet said surface of said substrate, and wherein said etching produces a ratio of vertical etch rates of said substrate to said mask of greater than 1.
Claim 2
Dependent Claim 71 words
A process for producing an article comprising the steps of forming a mask on the surface of a substrate and etching said substrate by anisotropic etching characterized in that said mask is formed by depositing onto said substrate a material that does not substantially wet said surface of said substrate, and wherein said etching produces a ratio of vertical etch rates of said substrate to said mask of greater than 1.
Claim 3
Dependent Claim 12 words
The process of claim 1 wherein said ratio is greater than 3.
Claim 4
Dependent Claim 10 words
The process of claim 2 wherein said substrate comprises tungsten.
Claim 5
Dependent Claim 10 words
The process of claim 1 wherein said substrate comprises tungsten.
Claim 6
Dependent Claim 17 words
The process of claim 3 or 4 wherein said etching is performed employing a CF 4 environment.
Claim 7
Dependent Claim 19 words
The process of claim 1 wherein said substrate comprises a layer of tungsten and a layer of silicon oxide.
Claim 8
Dependent Claim 12 words
The process of claim 1 wherein said etching is reactive ion etching.
Claim 9
Dependent Claim 15 words
The process of claim 7 wherein said etching is performed in a CF 4 environment.
Claim 10
Dependent Claim 16 words
The process of claim 7 wherein said etching is performed in a CF 3 Br environment.
Claim 11
Dependent Claim 24 words
The process of claim 1 wherein said etching is reactive ion etching done sequentially in an environment of CHF 3 and CF 3 Br.
Claim 12
Dependent Claim 24 words
The process of claim 1 wherein said etching is reactive ion etching done sequentially in an environment of CHF 3 and CF 4 .
Claim 13
Dependent Claim 22 words
The process of either claim 10 or 11 wherein said substrate comprises a layer of tungsten and a layer of silicon oxide.

References Cited (Backward Citations)

US3971684A Cited
US4203800A Cited
US4226665A Cited
US4284689A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1985-08-16 1986-02-15 1986-08-17 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1989-08-16 1990-02-15 1990-08-17 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1993-08-16 1994-02-15 1994-08-17 $7700.00 Window Closed / Lapsed

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