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Photomasks and method of fabrication thereof

Assignee: Individual
•
Filing: 1972-04-10
•
Granted: 1974-08-20
•
Expires: 1992-04-10
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Abstract

Abstract Photomasks and method of fabrication thereof, whereby a thin layer of germanium is deposited to a substrate which may be then etched in a pattern to provide a photomask or information storage device. In the fabrication method, a substrate is carried by belt through a first inert gas curtain into a furnace containing a mixture of suitable gases for causing the deposition of germanium onto the heated substrate, and there outward through a second inert gas curtain into a cooling region. The use of a germanium film for a mask blank results in a mask which is reasonably transparent to visible light but substantially opaque to ultravoilet light, and which may be deposited on to and removed from various substrates including glass using etchants which do not attack the substrate material.

Inventors

  • 👤 W Lehrer

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-25 20:34
CPC Classifications
G; G03; G03F; G03F1/00; G03F1/54; Y; Y10; Y10T; Y10T428/00; Y10T428/26; Y10T428/263; Y10T428/264; Y10T428/265

Claims Analysis

Total Claims: 5
Claim 1
Independent Claim 21 words
The photomask blank of claim 1 wherein said germanium film has a thickness in the range of 500 to 1,500 angstroms.
Claim 2
Dependent Claim 15 words
The photomask blank of claim 2 wherein said germanium film is a pyrolytically dEposited film.
Claim 3
Dependent Claim 11 words
The photomask of claim 3 wherein said germanium film is patterned.
Claim 4
Dependent Claim 29 words
A photomask blank comprising a glass substrate with a pyrolytically deposited germanium film on one surface thereof, said film having a thickness in the range 500 to 1,500 angstroms.
Claim 5
Dependent Claim 11 words
The photomask of claim 5 wherein said germanium film is patterned.

References Cited (Backward Citations)

US3271488A Cited
US3511683A Cited
US3561963A Cited
US3649393A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1977-08-19 1978-02-18 1978-08-20 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1981-08-19 1982-02-18 1982-08-20 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1985-08-19 1986-02-18 1986-08-20 $7700.00 Window Closed / Lapsed

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