The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 03, 1989
Filed:
May. 16, 1988
Michael Scardera, Hamden, CT (US);
Thomas S Roche, Cheshire, CT (US);
Olin Corporation, Cheshire, CT (US);
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: ##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.