Patent US5446125A successfully refreshed from Google Patents.
US5446125A
Expired / Lapsed
US
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Method for removing metal impurities from resist components
Assignee: Olin Microelectronic Chemicals Inc
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Filing: 1991-09-03
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Granted: 1995-08-29
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Expires: 2011-09-03
Abstract
Abstract A method of removing metal impurities from a resist component, comprising the steps of: (a) dissolving said resist component in a solvent; (b) contacting said resist component solution with a cation exchange resin and a chelate resin for a sufficient amount of time to absorb at least a portion of said metal impurities onto said cation exchange and chelate resins; and (c) separating said cation exchange and chelate resins bearing said metal impurities from said resist component solution.
Inventors
- 👤 Kenji Honda
- 👤 Edward A. Fitzgerald
- 👤 Lawrence Ferreira
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 07:01
CPC Classifications
C; C08; C08F; C08F6/00; C08F6/06
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
123 words
A method of removing metal impurities from a resist component comprising the steps of: (a) dissolving said resist component in a solvent; (b) contacting said resist component solution with a cation exchange resin and a chelate resin, for a sufficient amount of time to absorb at least a portion of said metal impurities onto said cation exchange resin and said chelate resin, wherein said cation exchange resin and, optionally said chelate resin, are prewashed with a solution of a quaternary ammonium salt compound and wherein the weight ratio of said chelate resin to said cation exchange resin is from about 9:1 to 1:9; and (c) separating said cation exchange resin and said chelate resin bearing said metal impurities from said resist component solution.
Claim 2
Independent Claim
123 words
A method of removing metal impurities from a resist component comprising the steps of: (a) dissolving said resist component in a solvent; (b) contacting said resist component solution with a cation exchange resin and a chelate resin, for a sufficient amount of time to absorb at least a portion of said metal impurities onto said cation exchange resin and said chelate resin, wherein said cation exchange resin and, optionally said chelate resin, are prewashed with a solution of a quaternary ammonium salt compound and wherein the weight ratio of said chelate resin to said cation exchange resin is from about 9:1 to 1:9; and (c) separating said cation exchange resin and said chelate resin bearing said metal impurities from said resist component solution.
Claim 3
Dependent Claim
22 words
The method of claim 1 wherein said resist component solution is contacted simultaneously with said cation exchange resin and said chelate resin.
Claim 4
Dependent Claim
22 words
The method of claim 1 wherein said resist component solution is contacted sequentially with said cation exchange resin and said chelate resin.
Claim 5
Dependent Claim
16 words
The method of claim 1 wherein said solvent comprises ethyl lactate, ethyl-3-ethoxy propionate and mixtures thereof.
Claim 6
Dependent Claim
16 words
The method of claim 1 wherein said metal impurities comprise a mixture of sodium and iron.
Claim 7
Dependent Claim
11 words
The method of claim 1 wherein said separating step is filtration.
Claim 8
Dependent Claim
35 words
The method of claim 1 wherein said contacting step (b) is sufficient to cause said resist component solution to contain less than 100 ppb each of sodium and iron after said metal separation step (c).
Claim 9
Dependent Claim
13 words
The method of claim 1 wherein said resist component is a novolak resin.
Claim 10
Dependent Claim
16 words
The method of claim 1 wherein said quaternary ammonium salt compound is a tetra-alkyl ammonium hydroxide.
Claim 11
Dependent Claim
25 words
The method of claim 1 wherein the mode of contacting comprises adding said cation exchange resin and said chelate resin to said resist component solution.
Claim 12
Dependent Claim
35 words
The method of claim 1 wherein said contacting and separating steps comprise passing said resist component solution through at least one ion exchange column or bed containing said cation exchange resin and said chelate resin.
Claim 13
Dependent Claim
13 words
The method of claim 1 wherein said chelate resin has polyamine chelating groups.
Claim 14
Dependent Claim
16 words
The method of claim 1 wherein said cation exchange resin is a fibrous cation exchange resin.
Claim 15
Dependent Claim
18 words
The method of claim 1 wherein said quaternary ammonium salt compound is a polymeric quaternary ammonium salt compound.
Claim 16
Independent Claim
128 words
A method of removing metal impurities from a novolak resin, comprising the steps of: (a) dissolving said novolak resin in a solvent; (b) contacting said novolak resin solution with an admixture of at least one cation exchange resin and at least one chelate resin for sufficient amount of time to transfer at least a major portion of said metal impurities onto said cation exchange resin and said chelate resin, wherein said cation exchange resin and, optionally said chelate resin are prewashed with a solution of a quaternary ammonium salt compound and wherein the weight ratio of said chelate resin to said cation exchange resin is from about 9:1 to 1:9; and (c) separating said cation exchange and chelate resins bearing said metal impurities from said novolak resin solution.
Claim 17
Independent Claim
128 words
A method of removing metal impurities from a novolak resin, comprising the steps of: (a) dissolving said novolak resin in a solvent; (b) contacting said novolak resin solution with an admixture of at least one cation exchange resin and at least one chelate resin for sufficient amount of time to transfer at least a major portion of said metal impurities onto said cation exchange resin and said chelate resin, wherein said cation exchange resin and, optionally said chelate resin are prewashed with a solution of a quaternary ammonium salt compound and wherein the weight ratio of said chelate resin to said cation exchange resin is from about 9:1 to 1:9; and (c) separating said cation exchange and chelate resins bearing said metal impurities from said novolak resin solution.
Claim 18
Dependent Claim
26 words
The method of claim 15 wherein said contacting is carried out by adding said admixture of cation exchange and chelate resins to said novolak resin solution.
Claim 19
Dependent Claim
38 words
The method of claim 15 wherein said contacting and separating steps are carried out by passing said novolak resin solution through at least one ion exchange column or bed comprising an admixture of cation exchange and chelate resins.
Claim 20
Dependent Claim
15 words
The method of claim 15 wherein said quaternary ammonium salt compound is tetramethyl ammonium hydroxide.
Claim 21
Dependent Claim
13 words
The method of claim 15 wherein said chelate resin has polyamine chelating groups.
Claim 22
Dependent Claim
16 words
The method of claim 15 wherein said cationic exchange resin is a fibrous cation exchange resin.
Claim 23
Dependent Claim
17 words
The method of claim 15 wherein said quaternary ammonium salt compound is apolymeric quaternary ammonium salt compound.
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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) | 1998-08-28 | 1999-02-27 | 1999-08-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-08-28 | 2003-02-27 | 2003-08-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-08-28 | 2007-02-27 | 2007-08-29 | $7700.00 | Window Closed / Lapsed |