Allied Corporation

Hmc Patents Holding Co., Inc.

Evan G Thomas

Harold J Kieta

Ronald J Hopkins

Kane David Cook

Edmund W Smalley

Piperazine containing positive photoresist stripping compositions are provided. Formulations include N-aminoalkylpiperazines with the formula ##STR1## bis-N-aminoalkylpiperazines of the formula ##STR2## N-hydroxyalkylpiperazine of the formula ##STR3## and bis-hydroxyalkypiperazines with structure ##STR4## In the above formulae n=1-6. Also included are piperazine derivatives such as those of the above formulae with a branch chain alkyl of 1-6 C atoms, and 5-6 atom cycloalkyl substituted compounds wherein the cycloalkyl is substituted for --(CH.sub.2).sub.n --. Components which may be mixed with the above described piperazine in preparing the positive photoresist stripping compositions of the invention include alkyl or cycloalkyl-2-pyrrolidones of the formula ##STR5## Other amide type solvents with the boiling point in excess of 200.degree. C. as well as high boiling diethylene glycol ethers may also be incorporated.

Positive photoresist stripping composition

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 ##STR1## where X is F, H, Cl, OH, SO.sub.3 A 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 NH.sub.4.sup.+, H.sup.+, Na.sup.+, K.sup.+, Li.sup.+, R.sup.+ or organic amine cations.

Soluble fluorinated cycloalkane sulfonate surfactant additives for NH.sub.4

Silicon trioxide etching solutions with soluble surfact additives are provided. The improved silicon dioxide etchants are produced by adding soluble perfluornated surfactant additives to standard oxide etchants in the manufacture of integrated circuits. These surfactant additives are unique because they remain dissolved in the oxide etchant (ammonium fluoride/hydrofluoric acid mixture) even after 0.2 micron filtration. In addition, the filtered solutions retain their surface active properties and are low in metallic ion impurities. The surfactant additives provide etchant solutions with lower surface tensions, which improves substrate wetting and yields better etchant performance. The surfactant does not leave residues or adversely affect etchant profiles.

Soluble surfactant additives for ammonium fluoride/hydrofluoric acid

Stripping solution compositions which avoid the problem know as 'brown staining' are provided. Relevant stripping solutions are those that are free from phenol and chlorinated hydrocarbon compounds and comprise a surfactant alkylarylsulfonic acid having 12-20 carbons, a hydrotropic aromatic sulfonic acid having 6-9 carbons and a halogen-free aromatic hydrocarbon solvent with a boiling point above 150.degree. C. To suppress brown staining, a water soluble sulfone is incorporated into the stripping solution. The stripping compositions effectively remove organic polymeric substances from inorganic substrates and are substantially clear water rinsable.

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East Aurora, NY, United States of America

Evan G Thomas