US4620934A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Soluble fluorinated cycloalkane sulfonate surfactant additives for NH4
Assignee: KRONE INTERNATIONAL HOLDING Inc (SUCCESSOR TO HMC PATENT HOLDING Co INC)
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Filing: 1985-05-13
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Granted: 1986-11-04
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Expires: 2005-05-13
Abstract
Abstract Silicon dioxide etching solutions with soluble surfactant additives are provided. The improved silicon dioxide etchants are produced by adding soluble fluorinated surfactant additives to standard oxide etchants in the manufacture of integrated circuits. The surfactants found effective in accordance with the invention are referred to as fluorinated cycloalkane sulfonates and fluorinated cycloalkene sulfonates and have the general formula <IMAGE> where X is F, H, Cl, OH, SO3A or R and Y is F, H, OH, R or be omitted and thereby impart a double bond; wherein R is a 1 to 4 fluoroalkyl group; and wherein n has a value of up to 6. A represents as the cation group may be NH4+, H+, Na+, K+, Li+, R+ or organic amine cations.
Inventors
- 👤 Ronald J. Hopkins
- 👤 Evan G. Thomas
- 👤 Harold J. Kieta
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 14:51
CPC Classifications
C; C04; C04B; C04B41/00; C04B41/53; 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: 12
Claim 1
Independent Claim
141 words
An etching solution containing a surfactant, which is stable against the precipitation of the surfactant, comprising an aqueous mixture of ammonium fluoride and surfactant that contains between 13.5 and 45 weight percent ammonium fluoride (NH 4 F) and between 25 and 2000 ppm of a fluorinated sulfonate selected from the group consisting of cycloalkane sulfonate, fluorinated cycloalkene sulfonate of the formula: ##STR6## wherein n has a value of up to 6, X may be F, Cl, H, OH, SO 3 A or R and Y may be F, Cl, H, OH, R' or be a double bond and A may be H, NH + , Na + , K + , Li + , R" + or NR" 4 + wherein R" is a 1 to 4 carbon atom alkyl and/or fluoroalkyl group and mixtures thereof and the remainder being water.
Claim 2
Dependent Claim
141 words
An etching solution containing a surfactant, which is stable against the precipitation of the surfactant, comprising an aqueous mixture of ammonium fluoride and surfactant that contains between 13.5 and 45 weight percent ammonium fluoride (NH 4 F) and between 25 and 2000 ppm of a fluorinated sulfonate selected from the group consisting of cycloalkane sulfonate, fluorinated cycloalkene sulfonate of the formula: ##STR6## wherein n has a value of up to 6, X may be F, Cl, H, OH, SO 3 A or R and Y may be F, Cl, H, OH, R' or be a double bond and A may be H, NH + , Na + , K + , Li + , R" + or NR" 4 + wherein R" is a 1 to 4 carbon atom alkyl and/or fluoroalkyl group and mixtures thereof and the remainder being water.
Claim 3
Dependent Claim
15 words
An etching solution according to claim 1 containing up to 11 weight percent hydrogen fluoride.
Claim 4
Dependent Claim
20 words
The etching solution of claim 1 wherein "n" in the fluorinated cyclic surfactant has a value of 2 to 4.
Claim 5
Dependent Claim
21 words
The etching solution of claim 1 wherein the fluorinated cyclic surfactant is the ammonium salt having a low metal ion content.
Claim 6
Dependent Claim
20 words
The etching solution of claim 1 wherein the fluorinated cycloalkane or cycloalkene sulfonate is fluorinated cycloalkane or cycloalkene sulfonic acid.
Claim 7
Dependent Claim
41 words
An etching solution of claim 1 wherein the fluorinated cyclo surfactant is present in smounts of 200 to 5000 ppm and is added to the etchant solution as a dry solid or as a solution in an aqueous polar solvent mixture.
Claim 8
Dependent Claim
27 words
An etching solution according to claim 1 containing up to 11 weight percent hydrogen fluoride, between 200 and 1000 ppm fluorinated cyclic surfactant diluent to lessen corrosion.
Claim 9
Dependent Claim
35 words
The etching solution of claim 2 containing up to 50 weight percent as a corrosion depressing diluent selected from the group consisting of acetic acid, ethylene glycol, and a 1 to 3 carbon atom alcohol.
Claim 10
Dependent Claim
37 words
A process for producing an etching solution which comprises blending 49% by weight aqueous hydrogen fluoride and a 15% to 40% by weight aqueous solution of ammonium fluoride, with 200 to 5000 ppm active fluorinated cyclic surfactant.
Claim 11
Dependent Claim
37 words
A process for producing an etching solution which comprises blending 49% by weight aqueous hydrogen fluoride and a 15% to 40% by weight aqueous solution of ammonium fluoride, with 200 to 5000 ppm active fluorinated cyclic surfactant.
Claim 12
Dependent Claim
19 words
The process according to claim 9 wherein the aqueous ammonium fluoride contains about 30% NH 4 F by weight.
References Cited (Backward Citations)
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) | 1989-11-03 | 1990-05-05 | 1990-11-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-11-03 | 1994-05-05 | 1994-11-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-11-03 | 1998-05-05 | 1998-11-04 | $7700.00 | Window Closed / Lapsed |