The novel etching composition

PROBLEM TO BE SOLVED: To provide an etching composition which is suitable to selectively etch selected metals with little or no damage to adjacent materials and structures.SOLUTION: An etching composition comprises: at least one sulfonic acid; at least one compound containing a halide anion, the halide anion being chloride or bromide; at least one compound containing a nitrate or nitrosyl ion; and water. The at least one sulfonic acid is approximately 25-95 wt.% of the etching composition. The halide anion is chloride or bromide, and is approximately 0.01-0.5 wt.% of the composition. The nitrate or nitrosyl ion is approximately 0.1-20 wt.% of the composition. The water is at least approximately 3 wt.% of the composition.SELECTED DRAWING: None