US4284706A
Expired / Lapsed
US
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Lithographic resist composition for a lift-off process
Assignee: International Business Machines Corp
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Filing: 1979-12-03
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Granted: 1981-08-18
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Expires: 1999-12-03
Abstract
Abstract Lithographic resist compositions are provided which permit an improved lift-off process in which the deposition mask with apertures has the desirable negative slope or overhang. The resist composition comprises a phenolic-aldehyde resin, a photosensitizer and Meldrum's diazo, or Meldrum's acid or suitable analogs thereof as a profile modifying agent. The profile modifying agents useful in the present invention have the formula: ##STR1## wherein R 1 is C 1 to C 20 alkyl or aryl, R 2 is H, C 1 to C 20 alkyl or aryl, or together R 1 and R 2 are cycloalkyl, A is N or H.
Inventors
- 👤 Nicholas J. Clecak
- 👤 Barbara D. Grant
- 👤 Carlton G. Willson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 10:53
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/004; G03F7/016; G03F7/0163; G03F7/022; G03F7/0226
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
87 words
A lithographic resist composition for use in a lift-off process with ultra-violet light to form a mask with apertures having a negative slope comprising a phenolic-aldehyde resin, a naphthoquinone diazide sulfonic acid ester sensitizer and in admixture therewith a profile modifying agent having the formula ##STR6## wherein R 1 is alkyl or aryl having up to 20 carbon atoms, R 2 is H, alkyl or aryl having up to 20 carbon atoms, or together R 1 and R 2 are cycloalkyl and A is N or H.
Claim 2
Dependent Claim
87 words
A lithographic resist composition for use in a lift-off process with ultra-violet light to form a mask with apertures having a negative slope comprising a phenolic-aldehyde resin, a naphthoquinone diazide sulfonic acid ester sensitizer and in admixture therewith a profile modifying agent having the formula ##STR6## wherein R 1 is alkyl or aryl having up to 20 carbon atoms, R 2 is H, alkyl or aryl having up to 20 carbon atoms, or together R 1 and R 2 are cycloalkyl and A is N or H.
Claim 3
Dependent Claim
24 words
A composition as claimed in claim 1 wherein the release material is present in an amount of from about 5% to the saturation level.
Claim 4
Dependent Claim
14 words
A composition as claimed in claim 1 wherein the resin is a cresol-formaldehyde resin.
Claim 5
Dependent Claim
15 words
A composition as claimed in claim 1 wherein the profile modifying agent is Meldrum's diazo.
Claim 6
Dependent Claim
46 words
A lithographic resist composition for use in a lift-off process with ultra-violet light to form a mask with apertures having a negative slope comprising a phenolic-aldehyde resin, a naphthoquinone diazide sulfonic acid ester sensitizer and in admixture therewith a profile modifying agent that is Meldrum's acid.
Claim 7
Dependent Claim
46 words
A lithographic resist composition for use in a lift-off process with ultra-violet light to form a mask with apertures having a negative slope comprising a phenolic-aldehyde resin, a naphthoquinone diazide sulfonic acid ester sensitizer and in admixture therewith a profile modifying agent that is Meldrum's acid.
Claim 8
Dependent Claim
128 words
A lift-off process for forming a lithographic resist image comprising baking a film comprising a phenolic-aldehyde resin, a naphthoquinone diazide sulfonic acid ester sensitizer and in admixture therewith a profile modifying agent having the formula ##STR7## wherein R 1 is alkyl or aryl having up to 20 carbon atoms, R 2 is H, alkyl or aryl having up to 20 carbon atoms, or together R 1 and R 2 are cycloalkyl, and A is N or H at a temperature for a time sufficient for said profile modifying agent to form a skin at the surface of said film, image-wise exposing said baked film to ultraviolet light, and dissolving the exposed portions of said film with aqueous alkali to form a mask with apertures having a negative slope.
Claim 9
Dependent Claim
128 words
A lift-off process for forming a lithographic resist image comprising baking a film comprising a phenolic-aldehyde resin, a naphthoquinone diazide sulfonic acid ester sensitizer and in admixture therewith a profile modifying agent having the formula ##STR7## wherein R 1 is alkyl or aryl having up to 20 carbon atoms, R 2 is H, alkyl or aryl having up to 20 carbon atoms, or together R 1 and R 2 are cycloalkyl, and A is N or H at a temperature for a time sufficient for said profile modifying agent to form a skin at the surface of said film, image-wise exposing said baked film to ultraviolet light, and dissolving the exposed portions of said film with aqueous alkali to form a mask with apertures having a negative slope.
Claim 10
Dependent Claim
15 words
A process as claimed in claim 6 wherein the profile modifying agent is Meldrum's diazo.
Claim 11
Dependent Claim
25 words
A process as claimed in claim 6 wherein the profile modifying agent is present in an amount of from about 5% to the saturation level.
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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) | 1984-08-17 | 1985-02-16 | 1985-08-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-08-17 | 1989-02-16 | 1989-08-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-08-17 | 1993-02-16 | 1993-08-18 | $7700.00 | Window Closed / Lapsed |