Olin Corporation

Thomas S Roche

Michael Scardera

Maureen F Preuss

An aqueous etchant solution made from water, hydrogen fluoride and a polyammonium fluoride salt selected from the group consisting of ethylenediammonium difluoride and diethylenetriammonium trifluoride.

Etchant solutions containing hydrogen fluoride and a polyammonium

An etchant solution comprised of water and:

Etchant solution for photoresist-patterned metal layers

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: ##STR1## 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 NH.sub.4 F 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.

Etching solutions containing ammonium fluoride and anionic sulfate

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 amine glycidol adduct. Preferred embodiments of the nonionic alkyl amine glycidol adducts employed in the etching solution of the present invention are those represented by the formulas: ##STR1## wherein R represents an alkyl group having from about 8 to about 18 carbon atoms and mixtures thereof,

Etching solutions containing ammonium fluoride and a nonionic alkyl

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:

Etching solutions containing ammonium fluoride and an alkyl

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: ##STR1## 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 NH.sub.4 F 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.

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Cheshire, CT, United States of America

Thomas S Roche