US4871422A
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Etching solutions containing ammonium fluoride and anionic sulfate esters of alkylphenol polyglycidol ethers and method of etching
Assignee: Olin Corp
•
Filing: 1988-05-16
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Granted: 1989-10-03
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Expires: 2008-05-16
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 an anionic sulfate ester of alkylphenol polyglycidol ether. Preferred embodiments of the anionic sulfate esters of alkylphenol polyglycidol ethers may be represented by the formula: <IMAGE> (I) wherein R represents an alkyl group having from about 4 to about 12 carbon atoms, x is from about 3 to about 15, M represents H, an alkali metal, an alkaline earth metal, ammonium, or an amine, and y is from 0.2 to about 4. The etching solutions preferably contain hydrogen fluoride in a volume ratio of NH4F to HF to from about 3:1 to about 50:1. The novel etching solutions of the present invention have excellent wetting characteristics and retain their wetting properties after extended periods of continuous filtration through sub-micron filters.
Inventors
- 👤 Michael Scardera
- 👤 Thomas S. Roche
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 00:40
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/28; H10P50/282; H10P50/283; C; C09; C09K; C09K13/00; C09K13/04; C09K13/08
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
24 words
An etching solution comprising an aqueous solution of ammonium fluoride and a wetting amount of an anionic sulfate ester of an alkylphenol polyglycidol ether.
Claim 2
Dependent Claim
24 words
An etching solution comprising an aqueous solution of ammonium fluoride and a wetting amount of an anionic sulfate ester of an alkylphenol polyglycidol ether.
Claim 3
Dependent Claim
20 words
The etching solution of claim 1 containing at least 0.1 moles of sulfate ester or a water soluble sulfate salt.
Claim 4
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 5
Dependent Claim
29 words
The etching solution of claim 1 in which the wetting amount of anionic alkylphenol polyglycidol ether sulfate is from about 5 to about 50,000 parts per million by weight.
Claim 6
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 100:1.
Claim 7
Dependent Claim
68 words
The etching solution of claim 1 in which the anionic sulfate ester of an alkylphenyl polyglycidol ether is represented by the formula: ##STR3## wherein R represents an alkyl group having from about 4 to about 12 carbon atoms, x is from about 3 to about 15, M represents H, an alkali metal, an alkaline earth metal, ammonium, or an amine, and y is from 0.2 to about 4.
Claim 8
Dependent Claim
17 words
The etching solution of claim 6 in which M represents an alkali metal, ammonium, or an amine.
Claim 9
Dependent Claim
22 words
The etching solution of claim 6 in which R represents an alkyl group having from about 8 to about 12 carbon atoms.
Claim 10
Dependent Claim
16 words
The etching solution of claim 8 in which x is from about 6 to about 12.
Claim 11
Dependent Claim
15 words
The etching solution of claim 9 in which y is from 1 to about 3.
Claim 12
Dependent Claim
11 words
The etching solution of claim 10 in which M represents ammonium.
Claim 13
Dependent Claim
25 words
The etching solution of claim 11 in which the ammonium fluoride is present in concentrations of from about 15 to about 40 percent by weight.
Claim 14
Dependent Claim
29 words
The etching solution of claim 12 in which hydrogen fluoride is present and the volume ratio of NH 4 F to HF is from about 3:1 to about 100:1.
Claim 15
Dependent Claim
23 words
The etching solution of claim 13 in which the wetting amount is from about 25 to about 30,000 parts per million by weight.
Claim 16
Dependent Claim
20 words
The etching solution of claim 13 in which R represents an alkyl group which is primarily in the para position.
Claim 17
Dependent Claim
13 words
The etching solution of claim 15 in which R represents the nonyl group.
Claim 18
Dependent Claim
16 words
The etching solution of claim 16 in which x is from about 6 to about 12.
Claim 19
Dependent Claim
37 words
A process for etching a silicon dioxide coated substrate which comprises immersing the substrate in a aqueous etching solution comprised of ammonium fluoride and a wetting amount of an anionic sulfate ester of an alkylphenol polyglycidol ether.
Claim 20
Dependent Claim
37 words
A process for etching a silicon dioxide coated substrate which comprises immersing the substrate in a aqueous etching solution comprised of ammonium fluoride and a wetting amount of an anionic sulfate ester of an alkylphenol polyglycidol ether.
Claim 21
Dependent Claim
24 words
The process of claim 18 in which the ammonium fluoride is present in concentrations of from about 15 to about 40 percent by weight.
Claim 22
Dependent Claim
28 words
The process of claim 19 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 23
Dependent Claim
32 words
The process of claim 18 in which the wetting amount of anionic sulfate ester of an alkylphenol polyglycidol ether sulfate is from about 5 to about 50,000 parts per million by weight.
Claim 24
Dependent Claim
67 words
The process of claim 18 in which the anionic sulfate ester of an alkylphenyl polyglycidol ether is represented by the formula: ##STR4## wherein R represents an alkyl group having from about 4 to about 12 carbon atoms, x is from about 3 to about 15, M represents H, an alkali metal, an alkaline earth metal, ammonium, or an amine, and y is from 0.2 to about 4.
Claim 25
Dependent Claim
22 words
The process of claim 22 in which M represents ammonium or an amine and x is from about 6 to about 12.
Claim 26
Dependent Claim
21 words
The process of claim 23 in which R represents an alkyl group having from about 8 to about 12 carbon atoms.
Claim 27
Dependent Claim
15 words
The process of claim 24 in which y is from about 1 to about 3.
Claim 28
Dependent Claim
25 words
The etching solution of claim 25 in which the ammonium fluoride is present in concentrations of from about 15 to about 40 percent by weight.
Claim 29
Dependent Claim
29 words
The etching solution of claim 26 in which hydrogen fluoride is present and the volume ratio of NH 4 F to HF is from about 3:1 to about 100:1.
Claim 30
Dependent Claim
21 words
The process of claim 27 in which R represents the nonyl group and x is from about 6 to about 12.
Claim 31
Dependent Claim
22 words
The process of claim 28 in which the wetting amount is from about 25 to about 30,000 parts per million by weight.
References Cited (Backward Citations)
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