Allied Corporation

Ronald J Hopkins

Evan G Thomas

Harold J Kieta

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.

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Orchard Park, NY, United States of America

Ronald J Hopkins