US4761244A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Etching solutions containing ammonium fluoride and an alkyl polyaccharide surfactant
Assignee: Olin Corp
•
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 alkyl polysaccharide having the formula: RO(R'O)xZy wherein R is alkyl, alkylphenol, hydroxyalkyl, hydroxy alkylphenol, or mixtures thereof and said alkyl groups contain from about 6 to about 18 carbon atoms, R' contains from 1 to about 4 carbon atoms, x is from 0 to about 5, Z is a moiety derived from a reducing saccharide containing from 5 to 6 carbon atoms, and y is from about 1 to about 5. 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
2026-10-29 22:55
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
93 words
An etching solution comprising an aqueous solution of ammonium fluoride and a wetting amount of a nonionic alkyl polysaccharide having the formula: RO(R'O).sub.x Z.sub.y wherein R is alkyl, alkylphenol, hydroxyalkyl, hydroxy alkylphenol, or mixtures thereof and said alkyl groups contain from about 6 to about 18 carbon atoms, R'O is an alkoxide moiety which contains from 1 to about 4 carbon atoms, x is from 0 to about 5, Z is a moiety derived from reducing saccharide containing from 5 to 6 carbon atoms, and y is from about 1 to about 5.
Claim 2
Dependent Claim
93 words
An etching solution comprising an aqueous solution of ammonium fluoride and a wetting amount of a nonionic alkyl polysaccharide having the formula: RO(R'O).sub.x Z.sub.y wherein R is alkyl, alkylphenol, hydroxyalkyl, hydroxy alkylphenol, or mixtures thereof and said alkyl groups contain from about 6 to about 18 carbon atoms, R'O is an alkoxide moiety which contains from 1 to about 4 carbon atoms, x is from 0 to about 5, Z is a moiety derived from reducing saccharide containing from 5 to 6 carbon atoms, and y is from about 1 to about 5.
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
27 words
The etching solution of claim 1 in which the wetting amount of nonionic alkyl polysaccharide is from about 5 to about 50,000 parts per million by weight.
Claim 6
Dependent Claim
22 words
The etching solution of claim 3 in which R is an alkyl group having from about 8 to about 14 carbon atoms.
Claim 7
Dependent Claim
13 words
The etching solution of claim 5 in which x is 0 or 1.
Claim 8
Dependent Claim
16 words
The etching solution of claim 6 in which y is from about 1 to about 21/2.
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
19 words
The etching solution of claim 8 in which x is 0, and y is from 1 to about 2.
Claim 11
Dependent Claim
107 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 alkyl polysaccharide having the formula: RO(R'O).sub.x Z.sub.y wherein R is alkyl, alkylphenol, hydroxyalkyl, hydroxy alkyphenol, or mixtures thereof and said alkyl groups contain from about 6 to about 18 carbon atoms, R'O is an alkoxide moiety which contains from 1 to about 4 carbon atoms, x is from 0 to about 5, Z is a moiety derived from a reducing sacharide containing from 5 to 6 carbon atoms, and y is from about 1 to about 5.
Claim 12
Dependent Claim
107 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 alkyl polysaccharide having the formula: RO(R'O).sub.x Z.sub.y wherein R is alkyl, alkylphenol, hydroxyalkyl, hydroxy alkyphenol, or mixtures thereof and said alkyl groups contain from about 6 to about 18 carbon atoms, R'O is an alkoxide moiety which contains from 1 to about 4 carbon atoms, x is from 0 to about 5, Z is a moiety derived from a reducing sacharide containing from 5 to 6 carbon atoms, and y is from about 1 to about 5.
Claim 13
Dependent Claim
24 words
The process of claim 10 in which the ammonium fluoride 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
26 words
The process of claim 10 in which the wetting amount of nonionic alkyl polysaccharide is from about 5 to about 50,000 parts per million by weight.
Claim 16
Dependent Claim
21 words
The process of claim 12 in which R is an alkyl group having from about 8 to about 14 carbon atoms.
Claim 17
Dependent Claim
19 words
The process of claim 14 in which x is 0 and y is from about 1 to about 2.
Claim 18
Dependent Claim
22 words
The process of claim 15 in which the wetting amount is from about 25 to about 30,000 parts per million by weight.
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