US4078098A
Expired / Lapsed
US
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High energy radiation exposed positive resist mask process
Assignee: International Business Machines Corp
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Filing: 1974-05-28
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Granted: 1978-03-07
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Expires: 1994-05-28
Abstract
Abstract The development of high energy radiation exposed positive acrylate polymer resist layers by organic liquid developers, such as methyl isobutyl ketone, is improved by adding water to the ketone.
Inventors
- 👤 Charles A. Cortellino
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:06
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/26; G03F7/30; G03F7/32; Y; Y10; Y10S; Y10S430/00; Y10S430/143
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
127 words
In the formation of patterned resist masks in which a layer of a methyl methacrylate polymer is coated on a substrate, exposed to radiation in a patternwise manner by a scanning electron beam having an energy of from about 3 to 50KV to provide a dosage level of from about 3 to 30 microcoulombs per square centimeter, and the exposed portions removed from the substrate using methyl-isobutyl ketone which dissolves the exposed portions of the layer at a faster rate than the unexposed portions to produce a relief image of resist on said substrate, the improvement which comprises adding water to said ketone such that the water content of said ketone is from about 0.5% to about 2.2% by volume so as to increase the development rate.
Claim 2
Dependent Claim
127 words
In the formation of patterned resist masks in which a layer of a methyl methacrylate polymer is coated on a substrate, exposed to radiation in a patternwise manner by a scanning electron beam having an energy of from about 3 to 50KV to provide a dosage level of from about 3 to 30 microcoulombs per square centimeter, and the exposed portions removed from the substrate using methyl-isobutyl ketone which dissolves the exposed portions of the layer at a faster rate than the unexposed portions to produce a relief image of resist on said substrate, the improvement which comprises adding water to said ketone such that the water content of said ketone is from about 0.5% to about 2.2% by volume so as to increase the development rate.
Claim 3
Dependent Claim
34 words
The process of claim 1 in which the water content of said ketone is determined by analysis and water added to bring the water content to from about 0.5 to about 2.2% by volume.
Claim 4
Dependent Claim
43 words
The process of claim 1 wherein any moisture is removed from said ketone by placing it over a drying agent and the water content brought to from about 0.5 to about 2.2% by volume of water by adding water to said dry ketone.
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) | 1981-03-06 | 1981-09-05 | 1982-03-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-03-06 | 1985-09-05 | 1986-03-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-03-06 | 1989-09-05 | 1990-03-07 | $7700.00 | Window Closed / Lapsed |