US4156745A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electron sensitive resist and a method preparing the same
Assignee: International Business Machines Corp
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Filing: 1978-04-03
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Granted: 1979-05-29
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Expires: 1998-04-03
Abstract
Abstract A high speed high contrast electron resist composition comprising a copolymer of polymethylmethacrylate/methacrylic acid having incorporated therein a metal selected from the group consisting of lead, barium, calcium and strontium is disclosed. The metal is present in the range of from about 0.001% to about 10% by weight of the copolymer.
Inventors
- 👤 Michael Hatzakis
- 👤 David J. Webb
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 08:08
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/004; G03F7/039
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
181 words
A method for the production of a positive resist image comprising the steps of: (A) exposing a film of a non crosslinked polymeric material to electron beam radiation in a predetermined pattern wherein the polymeric material is comprised of: (a) polymerized alkyl methacrylate units wherein the alkyl group contains 1 to 4 carbon atoms and (b) polymerized units of a methacrylate salt of a metal chosen from the group consisting of barium, calcium, lead and strontium and wherein the amount of said alkyl methacrylate units (a) is from about 50 to about 99.99 mole % and the amount of the metal salt of methacrylic acid (b) is from about 50 to about 0.001 mole % based upon the total moles of (a) and (b) in said polymeric materials and wherein said metal present is in the amount of from about 0.001 to about 10% by weight of the copolymer; (B) continuing said exposure until substantial degradation of said polymeric material to lower molecular weight products is achieved in the exposed areas; and (C) removing the degraded products in the exposed areas.
Claim 2
Independent Claim
181 words
A method for the production of a positive resist image comprising the steps of: (A) exposing a film of a non crosslinked polymeric material to electron beam radiation in a predetermined pattern wherein the polymeric material is comprised of: (a) polymerized alkyl methacrylate units wherein the alkyl group contains 1 to 4 carbon atoms and (b) polymerized units of a methacrylate salt of a metal chosen from the group consisting of barium, calcium, lead and strontium and wherein the amount of said alkyl methacrylate units (a) is from about 50 to about 99.99 mole % and the amount of the metal salt of methacrylic acid (b) is from about 50 to about 0.001 mole % based upon the total moles of (a) and (b) in said polymeric materials and wherein said metal present is in the amount of from about 0.001 to about 10% by weight of the copolymer; (B) continuing said exposure until substantial degradation of said polymeric material to lower molecular weight products is achieved in the exposed areas; and (C) removing the degraded products in the exposed areas.
Claim 3
Dependent Claim
25 words
The method of claim 1 wherein said polymeric material consists essentially of a copolymer of said alkyl methacrylate and the metal salt of methacrylic acid.
Claim 4
Dependent Claim
25 words
The method of claim 1 wherein said polymeric material consists essentially of a copolymer of said alkyl methacrylate and the barium salt of methacrylic acid.
Claim 5
Dependent Claim
25 words
The method of claim 1 wherein said polymeric material consists essentially of a copolymer of said alkyl methacrylate and the calcium salt of methacrylic acid.
Claim 6
Dependent Claim
25 words
The method of claim 1 wherein said polymeric material consists essentially of a copolymer of said alkyl methacrylate and the lead salt of methacrylic acid.
Claim 7
Dependent Claim
25 words
The method of claim 1 wherein said polymeric material consists essentially of a copolymer of said alkyl methacrylate and the strontium salt of methacrylic acid.
Claim 8
Dependent Claim
24 words
The method of claim 3 wherein said barium is present in the amount of about 0.05 to about 0.45% by weight of the copolymer.
Claim 9
Dependent Claim
24 words
The method of claim 4 wherein said calcium is present in the amount of about 0.02 to about 0.035% by weight of the copolymer.
Claim 10
Dependent Claim
24 words
The method of claim 5 wherein said lead is present in the amount of about 1% to about 4% by weight of the copolymer.
Claim 11
Dependent Claim
25 words
The method of claim 6 wherein said strontium is present in the amount of from about 0.003 to about 0.02% by weight of the copolymer.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-05-28 | 1982-11-27 | 1983-05-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-05-28 | 1986-11-27 | 1987-05-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-05-28 | 1990-11-27 | 1991-05-29 | $7700.00 | Window Closed / Lapsed |