Etching solutions containing ammonium fluoride and anionic esters of alkylphenol polyglycidol ethers

Abstract From the Canadian patent

Abstract of the Disclosure, An etching solution for use for example, in, the manufacture of integrated circuits is comprised of an aqueous solution of ammonium fluoride and a wetting amount of a sulfate ester of an alkylphenol polyglycidol ether or an alkyl amine glycidol adduct. The etching solution preferably contains hydrogen fluoride in a volume ratio of NH4F to HF is from about 3:1 to about 100:1. The novel etching solutions of the present invention all retain their wetting properties after 0.2 micron filtration, even under continuous filtration conditions. Moreover, the etching solutions after filtering have the property of wetting substrates more effectively and yield more uniform …