abstract |
The invention relates to an aqueous acid bath for the electrodeposition of shiny and leveled copper coatings, characterized by a content of at least one benzothiazonium compound of the general formula in the R₁ C₁-C₅ alkyl, optionally substituted aryl or aralkyl, R₂ is hydrogen, C₁-C₅-alkyl or C₁-C₅-alkoxy, R₃ and R₄ are each C₁-C₅ alkyl and X represents an acid residue. |