US4004043A
Expired / Lapsed
US
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Nitrated polymers as positive resists
Assignee: International Business Machines Corp
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Filing: 1975-09-26
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Granted: 1977-01-18
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Expires: 1995-09-26
Abstract
Abstract Positive resists are made using polymers and copolymers of methacrylic acid, methacrylic anhydride, methyl methacrylate, methacrylimide, and N-alkyl-methacrylimides which have been nitrated in up to about 10% of the monomer units on the methyl groups branching off the polymer chain. Inclusion of the nitro groups results in an increase of over an order of magnitude in the speed of development of images when the polymers are used as positive resists.
Inventors
- 👤 Hiroyuki Hiraoka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 05:25
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/004; G03F7/039; Y; Y10; Y10S; Y10S430/00; Y10S430/143
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
86 words
A process for forming an image with a positive resist, said process comprising the steps of: 1. forming on a substrate a film comprising a polymer or copolymer of methacrylic acid, methacrylic anhydride, methyl methacrylate, methacrylimide, and N-alkyl-methacrylimides, said polymer or copolymer having been nitrated in up to about 10% of the monomer units on the methyl group branching off the polymer chain, 2. exposing said film in a predetermined pattern to radiation, and 3. removing the radiation exposed portion of said film with a solvent.
Claim 2
Dependent Claim
86 words
A process for forming an image with a positive resist, said process comprising the steps of: 1. forming on a substrate a film comprising a polymer or copolymer of methacrylic acid, methacrylic anhydride, methyl methacrylate, methacrylimide, and N-alkyl-methacrylimides, said polymer or copolymer having been nitrated in up to about 10% of the monomer units on the methyl group branching off the polymer chain, 2. exposing said film in a predetermined pattern to radiation, and 3. removing the radiation exposed portion of said film with a solvent.
Claim 3
Dependent Claim
13 words
A process as claimed in claim 1 wherein the radiation is electron beam.
Claim 4
Dependent Claim
13 words
A process as claimed in claim 1 wherein the radiation is ultra-violet light.
Claim 5
Dependent Claim
30 words
A process as claimed in claim 1 wherein from about 4% to about 7% of the monomer units have been nitrated on the methyl group branching off the polymer chain.
Claim 6
Dependent Claim
27 words
A process as claimed in claim 1 wherein the nitration is carried out in situ by contacting a polymer film with NO 2 or NO 2 Cl.
Claim 7
Dependent Claim
35 words
A process as claimed in claim 1 wherein the polymer film is methyl methacrylate nitrated in from about 4 to about 7% of the monomer units on the methyl group branching off the polymer chain.
Claim 8
Dependent Claim
41 words
A process as claimed in claim 1 wherein the polymer film is a copolymer of methyl methacrylate and methacrylic acid nitrated in from about 4 to about 7% of the monomer units on the methyl group branching off the polymer chain.
Claim 9
Dependent Claim
34 words
A process as claimed in claim 1 wherein the polymer film is methacrylimide nitrated in from about 4 to about 7% of the monomer units on the methyl group branching off the polymer chain.
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) | 1980-01-18 | 1980-07-19 | 1981-01-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-01-18 | 1984-07-19 | 1985-01-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-01-18 | 1988-07-19 | 1989-01-18 | $7700.00 | Window Closed / Lapsed |