US4663275A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Photolithographic method and combination including barrier layer
Assignee: Shin Etsu MicroSi Inc
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Filing: 1984-09-04
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Granted: 1987-05-05
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Expires: 2004-09-04
Abstract
Abstract Photolithographic methods employing a photoresist layer and a contrast enhancing photobleachable layer deposited thereon have certain disadvantages including compatibility and the tendency toward scum formation during stripping of the photobleachable layer. These problems are alleviated by the deposition of an aqueous alkali-soluble polymeric barrier layer such as poly(vinyl alcohol), which is removed simultaneously with the alkaline development step for the photoresist. In a preferred embodiment, the polymeric binder for the photobleachable layer is also water-soluble and is also removed simultaneously with development.
Inventors
- 👤 Paul R. West
- 👤 Gary C. Davis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 23:50
CPC Classifications
G; G03; G03C; G03C11/00; G03C11/06; G03F; G03F7/00; G03F7/004; G03F7/09; G03F7/091
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
118 words
A photolithographic method which comprises the steps of: (A) depositing a photoresist layer on an etchable substrate; (B) depositing an aqueous alkali-soluble, optically transparent polymeric barrier layer on said photoresist layer from a solvent which is non-aggressive to said photoresist layer; (C) depositing on said barrier layer a photobleachable layer comprising a polymeric binder and at least one photobleachable compound from a solvent which is non-aggressive to said barrier layer; (D) masking said layers and exposing them to light of a predetermined wavelength to which said photoresist layer and photobleachable compound are sensitive; (E) stripping said photobleachable layer; and (F) simultaneously developing said photoresist and stripping said barrier layer by contacting the same with an aqueous alkaline solution.
Claim 2
Dependent Claim
118 words
A photolithographic method which comprises the steps of: (A) depositing a photoresist layer on an etchable substrate; (B) depositing an aqueous alkali-soluble, optically transparent polymeric barrier layer on said photoresist layer from a solvent which is non-aggressive to said photoresist layer; (C) depositing on said barrier layer a photobleachable layer comprising a polymeric binder and at least one photobleachable compound from a solvent which is non-aggressive to said barrier layer; (D) masking said layers and exposing them to light of a predetermined wavelength to which said photoresist layer and photobleachable compound are sensitive; (E) stripping said photobleachable layer; and (F) simultaneously developing said photoresist and stripping said barrier layer by contacting the same with an aqueous alkaline solution.
Claim 3
Dependent Claim
35 words
A method according to claim 1 wherein the barrier layer polymer is a water-soluble polymer which is substantially resistant to any solvent used to deposit said photobleachable layer, and is applied from an aqueous solution.
Claim 4
Dependent Claim
39 words
A method according to claim 2 wherein the barrier layer polymer is at least one of poly(vinyl alcohol), poly(acrylic acid), poly(methacrylic acid), poly-(vinylpyrrolidone) and poly(ethylene oxide) and has a weight average molecular weight in the range of about 2000-12,000.
Claim 5
Dependent Claim
24 words
A method according to claim 3 wherein step E is effected prior to step F by contacting said photobleachable layer with an organic solvent.
Claim 6
Dependent Claim
17 words
A method according to claim 4 wherein the thickness of the barrier layer is about 300-2500 Angstroms.
Claim 7
Dependent Claim
18 words
A method according to claim 5 wherein the binder in the photobleachable layer is a styrene-allyl alcohol copolymer.
Claim 8
Dependent Claim
18 words
A method according to claim 6 wherein the solvent used in step E is toluene, xylene or trichloroethylene.
Claim 9
Dependent Claim
14 words
A method according to claim 7 wherein the barrier layer polymer is poly(vinyl alcohol).
Claim 10
Dependent Claim
25 words
A method according to claim 3 wherein the binder in the photobleachable layer is also aqueous alkali-soluble and steps E and F are accomplished simultaneously.
Claim 11
Dependent Claim
15 words
A method according to claim 9 wherein the binder in the photobleachable layer is poly(vinylpyrrolidone).
Claim 12
Dependent Claim
14 words
A method according to claim 10 wherein the barrier layer polymer is poly(vinyl alcohol).
Claim 13
Dependent Claim
44 words
A photolithographic combination comprising a etchable substrate; a positive-working photoresist layer deposited thereon; an aqueous alkali-soluble, optically transparent polymeric barrier layer on said photoresist layer; and a photobleachable layer comprising a polymeric binder and at least one photobleachable compound deposited on said barrier layer.
Claim 14
Dependent Claim
44 words
A photolithographic combination comprising a etchable substrate; a positive-working photoresist layer deposited thereon; an aqueous alkali-soluble, optically transparent polymeric barrier layer on said photoresist layer; and a photobleachable layer comprising a polymeric binder and at least one photobleachable compound deposited on said barrier layer.
Claim 15
Dependent Claim
41 words
A combination according to claim 12 wherein the barrier layer polymer is a water-soluble polymer which is also soluble in a medium which is non-aggressive to said photoresist layer and substantially resistant to any solvent used to deposit said photobleachable layer.
Claim 16
Dependent Claim
39 words
A combination according to claim 13 wherein the barrier layer polymer is at least one of poly(vinyl alcohol), poly(acrylic acid), poly(methacrylic acid), poly(vinylpyrrolidone) and poly(ethylene oxide) and has a weight average molecular weight in the range of about 2000-12,000.
Claim 17
Dependent Claim
23 words
A combination according to claim 14 wherein the photoresist layer comprises a novolak or poly(vinylphenol) resin containing a material capable of photoinitiated degradation.
Claim 18
Dependent Claim
17 words
A combination according to claim 15 wherein the thickness of the barrier layer is about 300-2500 Angstroms.
Claim 19
Dependent Claim
18 words
A combination according to claim 16 wherein the binder in the photobleachable layer is a styrene-allyl alcohol copolymer.
Claim 20
Dependent Claim
14 words
A combination according to claim 17 wherein the barrier layer polymer is poly(vinyl alcohol).
Claim 21
Dependent Claim
16 words
A combination according to claim 14 wherein the binder in the photobleachable layer is also alkalisoluble
Claim 22
Dependent Claim
23 words
A combination according to claim 19 wherein the photoresist layer comprises a novolak or poly(vinylphenol) resin containing a material capable of photoinitiated degradation.
Claim 23
Dependent Claim
17 words
A combination according to claim 20 wherein the thickness of the barrier layer is about 300-2500 Angstroms.
Claim 24
Dependent Claim
15 words
A combination according to claim 21 wherein the binder in the photobleachable layer is poly(vinylpyrrolidone).
Claim 25
Dependent Claim
14 words
A combination according to claim 22 wherein the barrier layer polymer is poly(vinyl alcohol).
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-05-04 | 1990-11-03 | 1991-05-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-05-04 | 1994-11-03 | 1995-05-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-05-04 | 1998-11-03 | 1999-05-05 | $7700.00 | Window Closed / Lapsed |