US5108874A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Composite useful in photolithography
Assignee: Shin Etsu MicroSi Inc
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Filing: 1989-08-23
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Granted: 1992-04-28
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Expires: 2009-08-23
Abstract
Abstract The image of an object with opaque and transparent regions having a contrast less than the contrast threshold of a layer of photoresist when light of a predetermined wavelength to which the photoresist is sensitive is passed through the object and onto the layer of photoresist is enhanced in contrast by the provision of a contrast enhancing layer contiguous to the surface of the photoresist to a value above the contrast threshold of the photoresist. The contrast enhancing layer is constituted of an aryl nitrone compound mixed with a suitable binder.
Inventors
- 👤 Bruce F. Griffing
- 👤 Paul R. West
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 23:02
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/004; G03F7/09; G03F7/091; C; C07; C07C; C07C255/00; C07C255/63; C07C255/64; C07C291/00; C07C291/02; C07D; C07D455/00; C07D455/03; C07D455/04
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
80 words
A composite useful in making microelectronic circuits comprising a silicon wafer, a photoresist formed on the surface of the silicon wafer and a photobleachable layer that has been formed in situ upon the surface of the photoresist opposite the silicon wafer by spin casting a mixture thereon comprising by weight (A) 100 parts of organic solvent, (B) 1 to 30 parts of inert organic polymer binder, and (C) 1 to 30 parts of an ultraviolet radiation sensitive photobleachable organic compound.
Claim 2
Dependent Claim
80 words
A composite useful in making microelectronic circuits comprising a silicon wafer, a photoresist formed on the surface of the silicon wafer and a photobleachable layer that has been formed in situ upon the surface of the photoresist opposite the silicon wafer by spin casting a mixture thereon comprising by weight (A) 100 parts of organic solvent, (B) 1 to 30 parts of inert organic polymer binder, and (C) 1 to 30 parts of an ultraviolet radiation sensitive photobleachable organic compound.
Claim 3
Dependent Claim
32 words
A composite in accordance with claim 1, where the photobleachable layer has a thickness of less than about 1 micron and the photoresist has a thickness of less than about 3 microns.
Claim 4
Dependent Claim
32 words
A composite in accordance with claim 1, where the photobleachable organic compound has an extinction coefficient to molecular weight ratio in liters per gram/cm in the unbleached state greater than about 10.
Claim 5
Dependent Claim
16 words
A composite in accordance with claim 1, where the photobleachable organic compound is a photoisomerizable compound.
Claim 6
Dependent Claim
16 words
A composite in accordance with claim 1, where the photobleachable organic compound is a photofragmentable compound.
Claim 7
Dependent Claim
15 words
A composite in accordance with claim 1, where the photobleachable organic compound is an arylnitrone.
Claim 8
Dependent Claim
53 words
A composite in accordance with claim 1, where the photobleachable layer is formed by spin casting a mixture upon the surface of the photoresist which comprises by weight (A) 100 parts of organic solvent, (B) 5 to 15 parts of inert polymer binder, and (C) 5 to 15 parts of photobleachable organic compound.
Claim 9
Dependent Claim
23 words
A composite in accordance with claim 1, where the photobleachable layer has an absorption maximum in the range of 300 to 450 nanometers.
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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) | 1995-04-28 | 1995-10-28 | 1996-04-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-04-28 | 1999-10-28 | 2000-04-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-04-28 | 2003-10-28 | 2004-04-28 | $7700.00 | Window Closed / Lapsed |