US5061024C1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Amorphous fluoropolymer pellicle films
Assignee: DU PONT CHEMICAL AND ENERGY OPERATIONS Inc
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Filing: 1989-09-06
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Granted: 2002-02-26
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Expires: 2009-09-06
Abstract
Abstract A pellicle comprising a thin, durable film of substantially uniform thickness which absorbs less than 10% light at wavelengths between 190 and 820 nanometers, tautly adhered to one edge of an enclosed support frame, said thin film comprising amorphous fluoropolymers having a refractive index between 1.24 and 1.41. Pellicles of this type are dust defocusing covers for photomasks and reticles used to project patterns onto light sensitive substrates such as photoresist-coated semiconductor wafers which are used in the manufacture of integrated circuits.
Inventors
- 👤 Dalen E Keys
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 21:53
CPC Classifications
G; G03; G03F; G03F1/00; G03F1/54; G03F1/62
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2005-02-25 | 2005-08-27 | 2006-02-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2009-02-25 | 2009-08-27 | 2010-02-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2013-02-25 | 2013-08-27 | 2014-02-26 | $7700.00 | Window Closed / Lapsed |