US4761245A
Expired / Lapsed
US
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Etching solutions containing ammonium fluoride and an alkylphenol polyglycidol ether surfactant
Assignee: Olin Corp
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Filing: 1987-01-27
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Granted: 1988-08-02
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Expires: 2007-01-27
Abstract
Abstract Etching solutions used to etch, for example, silicon dioxide coated substrates in the manufacture of integrated circuits comprise an aqueous solution of ammonium fluoride and a wetting amount of a nonionic alkylphenol polyglycidol ether having the formula: <IMAGE> wherein R is an alkyl group having from about 4 to about 12 carbon atoms, and x is from about 3 to about 15. The etching solutions preferably contain hydrogen fluoride in a volume ratio of NH4F to HF of from about 3:1 to about 50:1. The novel etching solutions of the present invention have excellent wetting characteristics, will not incorporate metallic ions, and retain their wetting properties after extended periods of continuous filtration.
Inventors
- 👤 Michael Scardera
- 👤 Thomas S. Roche
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 14:30
CPC Classifications
C; C09; C09K; C09K13/00; C09K13/04; C09K13/08; H; H10; H10P; H10P50/00; H10P50/20; H10P50/28; H10P50/282; H10P50/283
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
47 words
An etching solution comprising an aqueous solution of ammonium fluoride and a wetting amount of a nonionic alkylphenol polyglycidol ether having the formula: ##STR3## wherein R is an alkyl group having from about 4 to about 12 carbon atoms, and x is from about 3 toabout 15.
Claim 2
Dependent Claim
47 words
An etching solution comprising an aqueous solution of ammonium fluoride and a wetting amount of a nonionic alkylphenol polyglycidol ether having the formula: ##STR3## wherein R is an alkyl group having from about 4 to about 12 carbon atoms, and x is from about 3 toabout 15.
Claim 3
Dependent Claim
25 words
The etching solution of claim 1 in which the ammonium fluoride is present in concentrations of from about 15 to about 40 percent by weight.
Claim 4
Dependent Claim
29 words
The etching solution of claim 1 in which hydrogen fluoride is present and the volume ratio of NH 4 F to HF is from about 3:1 to about 50:1.
Claim 5
Dependent Claim
28 words
The etching solution of claim 1 in which the wetting amount of nonionic alkylphenol polyglycidol ether is from about 5 to about 50,000 parts per million by weight.
Claim 6
Dependent Claim
16 words
The etching solution of claim 4 in which x is from about 6 to about 12.
Claim 7
Dependent Claim
18 words
The etching solution of claim 4 in which R is from about 8 to about 12 carbon atoms.
Claim 8
Dependent Claim
16 words
The etching solution of claim 6 in which the R is primarily in the para position.
Claim 9
Dependent Claim
23 words
The etching solution of claim 7 in which the wetting amount is from about 25 to about 30,000 parts per million by weight.
Claim 10
Dependent Claim
17 words
The etching solution of claim 8 in which the alkylphenol polyglycidol ether is a nonylphenol polyglycidol ether.
Claim 11
Dependent Claim
61 words
A process for etching a silicon dioxide coated substrate which comprises immersing the substrate in an aqueous etching solution comprised of ammonium fluoride and a wetting amount of a nonionic alkylphenol polyglycidol ether having the formula: ##STR4## wherein R is an alkyl group having from about 4 to about 12 carbon atoms, and x is from about 3 to about 15.
Claim 12
Dependent Claim
61 words
A process for etching a silicon dioxide coated substrate which comprises immersing the substrate in an aqueous etching solution comprised of ammonium fluoride and a wetting amount of a nonionic alkylphenol polyglycidol ether having the formula: ##STR4## wherein R is an alkyl group having from about 4 to about 12 carbon atoms, and x is from about 3 to about 15.
Claim 13
Dependent Claim
24 words
The process of claim 10 in which the ammonium flouride is present in concentrations of from about 15 to about 40 percent by weight.
Claim 14
Dependent Claim
28 words
The process of claim 10 in which hydrogen fluoride is present and the volume ratio of NH 4 F to HF is from about 3:1 to about 50:1.
Claim 15
Dependent Claim
27 words
The process of claim 10 in which the wetting amount of nonionic alkylphenol polyglycidol ether is from about 5 to about 50,000 parts per million by weight.
Claim 16
Dependent Claim
15 words
The process of claim 12 in which x is from about 6 to about 12.
Claim 17
Dependent Claim
18 words
The process of claim 10 in which the R is from about 8 to about 12 carbon atoms.
Claim 18
Dependent Claim
23 words
The process of claim 15 in which the wetting a mount is from about 25 to about 30,000 parts per million by weight.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1991-08-02 | 1992-02-01 | 1992-08-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-08-02 | 1996-02-01 | 1996-08-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-08-02 | 2000-02-01 | 2000-08-02 | $7700.00 | Window Closed / Lapsed |