US5393642A
Expired / Lapsed
US
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Ionic modification of organic resins and photoresists to produce photoactive etch resistant compositions
Assignee: University of North Carolina at Charlotte
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Filing: 1992-12-31
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Granted: 1995-02-28
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Expires: 2012-12-31
Abstract
Abstract A photoresist composition is disclosed that comprises an organic resin that is thermoset by acid catalysis and a photoactive, etch-resistant ionic modifier formed of an anion and a cation. The modifier is present in the organic resin in an amount effective to produce substantial photoreactivity and etch resistance in a mixture of the resin and the modifier. The cation will, upon exposure to electromagnetic radiation, produce a species that is weakly basic or neutral, and the anion will, upon exposure to electromagnetic radiation, produce an acid precursor that will form a relatively strong acid in an acid-base solvent system. As a result, the relatively strong acid will catalyze the organic resin upon exposure to an appropriate frequency of electromagnetic radiation and the relatively weak base or neutral species formed by the cation will not substantially neutralize the acid or interfere with the acid catalyzed reaction of the organic resin.
Inventors
- 👤 Thomas D. DuBois
- 👤 Farid M. Tranjan
- 👤 Stephen M. Bobbio
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 05:55
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/004; G03F7/016; G03F7/0163; Y; Y10; Y10S; Y10S430/00; Y10S430/1053; Y10S430/1055; Y10S430/114; Y10S430/115; Y10S430/126
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
162 words
A photoresist composition comprising: an admixture of an organic resin that reacts in the presence of an acid; and a photoactive, etch resistant ionic modifier formed of an anion and a phosphonium cation, said modifier being present in said organic resin in an amount effective to produce substantial photoreactivity and etch resistance in a mixture of said resin and said modifier; said phosphonium cation being characterized in that it will, upon exposure to electromagnetic radiation, produce a photoreaction species that is weakly basic or neutral; and said anion being characterized in that it will, upon exposure to electromagnetic radiation, produce an acid precursor that will form a relatively strong acid in an acid-base solvent system; whereby said relatively strong acid will catalyze the organic resin upon exposure to an appropriate frequency of electromagnetic radiation and said relatively weak base or neutral species formed by said cation will neither substantially neutralize said acid nor interfere with the acid reaction of said organic resin.
Claim 2
Dependent Claim
162 words
A photoresist composition comprising: an admixture of an organic resin that reacts in the presence of an acid; and a photoactive, etch resistant ionic modifier formed of an anion and a phosphonium cation, said modifier being present in said organic resin in an amount effective to produce substantial photoreactivity and etch resistance in a mixture of said resin and said modifier; said phosphonium cation being characterized in that it will, upon exposure to electromagnetic radiation, produce a photoreaction species that is weakly basic or neutral; and said anion being characterized in that it will, upon exposure to electromagnetic radiation, produce an acid precursor that will form a relatively strong acid in an acid-base solvent system; whereby said relatively strong acid will catalyze the organic resin upon exposure to an appropriate frequency of electromagnetic radiation and said relatively weak base or neutral species formed by said cation will neither substantially neutralize said acid nor interfere with the acid reaction of said organic resin.
Claim 3
Dependent Claim
14 words
A photoresist composition according to claim 1 wherein said acid precursor is a radical.
Claim 4
Dependent Claim
22 words
A photoresist composition according to claim 1 wherein said phosphonium is selected from the group consisting of aryl, alkyl, and aryl-alkyl phosphoniums.
Claim 5
Dependent Claim
14 words
A photoresist composition according to claim 1 wherein said anion is a halide ion.
Claim 6
Dependent Claim
12 words
A photoresist composition according to claim 1 wherein said anion is iodide.
Claim 7
Dependent Claim
19 words
A photoresist according to claim 1 wherein said cation is selected from the group consisting of: triphenylfluorobutylphosphonium and tetrabutylphosphonium.
Claim 8
Dependent Claim
14 words
A photoresist composition according to claim 1 wherein said resin comprises a phenol-formaldehyde resin.
Claim 9
Dependent Claim
33 words
A photoresist composition according to claim 1 wherein said cation produces species that are weakly basic or neutral when said modifier is exposed to electromagnetic radiation in the visible portion of the spectrum.
Claim 10
Dependent Claim
34 words
A photoresist composition according to claim 1 wherein said cation produces a species that is weakly basic or neutral when said modifier is exposed to electromagnetic radiation in the ultraviolet portion of the spectrum.
Claim 11
Dependent Claim
31 words
A photoresist composition according to claim 1 wherein said modifier is present in an amount of between about 2 and 10% by weight based upon the weight of the resist composition.
Claim 12
Dependent Claim
41 words
A photoresist composition according to claim 1 wherein said anion produces an acid precursor that will form a relatively strong acid in an acid-base solvent system when said modifier is exposed to electromagnetic radiation in the visible portion of the spectrum.
Claim 13
Dependent Claim
41 words
A photoresist composition according to claim 1 wherein said anion produces an acid precursor that will form a relatively strong acid in an acid-base solvent system when said modifier is exposed to electromagnetic radiation in the ultraviolet portion of the spectrum.
Claim 14
Dependent Claim
35 words
A photoresist composition according to claim 1 wherein said anion produces an acid precursor that will form a relatively strong acid in an acid-base solvent system when said modifier is exposed to an electron beam.
Claim 15
Dependent Claim
40 words
A photoresist composition according to claim 1 wherein electromagnetic radiation will initiate a charge transfer reaction between said cation and said anion that produces said weakly basic or neutral species from said cation and said acid precursor from said anion.
Claim 16
Dependent Claim
14 words
A photoresist composition according to claim 1 wherein said organic resin is acid catalyzed.
Claim 17
Dependent Claim
19 words
A photoresist composition according to claim 1 wherein said organic resin is deprotonated in the presence of an acid.
Claim 18
Dependent Claim
19 words
A photoresist composition according to claim 1 wherein said organic resin is depolymerized in the presence of an acid.
Claim 19
Dependent Claim
12 words
A semiconductor device precursor surface coated with the photoresist of claim 1.
Claim 20
Dependent Claim
12 words
A semiconductor device precursor surface coated with the photoresist of claim 2.
References Cited (Backward Citations)
US4968582A
Cited
US5114827A
Cited
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