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US4997748A
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US
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Developer solution for positive-working resist composition
Assignee: Tokyo Ohka Kogyo Co Ltd
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Filing: 1989-08-16
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Granted: 1991-03-05
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Expires: 2009-08-16
Abstract
Abstract The developer solution of the invention is suitable for use to develop a positive-working resist composition comprising an alkali-soluble novolac resin and a naphthoquinone diazide compound and capable of giving a patterned image of the resist layer with a high contrast and increasing the effective depth of focus. The characteristic ingredient in the inventive developer solution is an alkali-soluble organic cyclic nitrogen compound such as N-hydroxyethyl piperazine, N-methyl-4-piperidone, 1,3-dimethyl-2-imidazolidinone and the like added in a specified concentration to a conventional developer solution containing tetramethyl ammonium hydroxide or choline as the water-soluble alkaline compound.
Inventors
- 👤 Yasuyuki Takeda
- 👤 Hatsuyuki Tanaka
- 👤 Toshimasa Nakayama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 07:56
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/26; G03F7/30; G03F7/32; G03F7/322
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
105 words
A developer solution for developing a positive-working resist composition comprising an alkali-soluble novolac resin and a naphthoquinone diazide compound, which solution comprises: (a) water as the solvent; (b) a water-soluble organic alkaline compound dissolved in the solvent in a concentration in the range from 1.0 to 10.0% by weight; and (c) an alkali-soluble organic cyclic nitrogen compound dissolved in the solvent in a concentration in the range from 0.1 to 10% by weight, wherein said compound is selected from the group consisting essentially of 2-hydroxyethyl pyridine, N-methyl piperazine, N-hydroxyethyl piperazine, 2-hydroxyethyl piperazine, N-hydroxyethyl piperazine, 2-methyl imidazole, 4-(2-hydroxyethyl) morpholine, 1-(2-hydroxyethyl) pyrrolidone, N-methyl-4-piperidone and 2-amino thiazole, 1,3-dimethyl-2-imidazolidinone.
Claim 2
Dependent Claim
105 words
A developer solution for developing a positive-working resist composition comprising an alkali-soluble novolac resin and a naphthoquinone diazide compound, which solution comprises: (a) water as the solvent; (b) a water-soluble organic alkaline compound dissolved in the solvent in a concentration in the range from 1.0 to 10.0% by weight; and (c) an alkali-soluble organic cyclic nitrogen compound dissolved in the solvent in a concentration in the range from 0.1 to 10% by weight, wherein said compound is selected from the group consisting essentially of 2-hydroxyethyl pyridine, N-methyl piperazine, N-hydroxyethyl piperazine, 2-hydroxyethyl piperazine, N-hydroxyethyl piperazine, 2-methyl imidazole, 4-(2-hydroxyethyl) morpholine, 1-(2-hydroxyethyl) pyrrolidone, N-methyl-4-piperidone and 2-amino thiazole, 1,3-dimethyl-2-imidazolidinone.
Claim 3
Dependent Claim
24 words
The developer solution as claimed in claim 1 wherein the water-soluble organic alkaline compound as the component (b) is tetramethyl ammonium hydroxide or choline.
Claim 4
Dependent Claim
31 words
The developer solution as claimed in claim 1 wherein the alkali-soluble organic cyclic nitrogen compound as the component (c) is selected from the group consisting of N-hydroxyethyl piperazine, N-methyl-4-piperidone and 1,3-dimethyl-2-imidazolidinone.
Claim 5
Dependent Claim
21 words
The developer solution as claimed in claim 3 wherein the alkali-soluble organic cyclic nitrogen compound as the component (c) is 1,3-dimethyl-2-imidazolidinone.
References Cited (Backward Citations)
EP0124297A2
Cited
EP0177905A2
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US4729941A
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EP0186184A2
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US4744834A
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US4820621A
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US4820621B1
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EP0286272A2
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-03-04 | 1994-09-03 | 1995-03-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-03-04 | 1998-09-03 | 1999-03-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-03-04 | 2002-09-03 | 2003-03-05 | $7700.00 | Window Closed / Lapsed |