Influence of organic ligands on copper electrodeposition from mono- and polyligand electrolytes

It is important to know the laws of copper electrodeposition from low-concentrated electrolytes containing different ligands because they simulate components of various copper-containing liquid wastes and electrolytes for electrodeposition of copper alloys with more electronegative metals. Aim: The aim of the research is to determine the characteristics of copper electrodeposition from low-concentrated mono- and polyligand electrolytes containing organic ligands. Materials and Methods: Electrolytes containing both inorganic (ammonia and pyrophosphate) and organic (tartrate, ethylenediaminetetraacetate, glycinate, sulfosalicylate) ligands were considered. Throwing power of electrolytes was determined using Hull cell. Results: It is shown that the copper electrodeposition in the presence of organic ligands occurs with high polarization and polarizability in comparison with sulphate electrolyte that leads to the deposition of fine-grained and uniform coating. The values of polarization and polarizability during cathodic copper electrodeposition from polyligand electrolyte containing ammonium and glycinate are between the values of polarization and polarizability during cathodic copper electrodeposition from monoligand (ammonia and glycinate) electrolytes. The addition of ethylenediaminetetraacetic acid disodium salt to copper pyrophosphate electrolyte leads to the depolarization of the copper reduction process, while addition of sulfosalicylate as additional ligand increases the copper discharge complications due to the delayed prior chemical stage of complex dissociation. The low-concentrated polyligand electrolyte based on the mixed pyrophosphate-sulfosalicylate complexes can be recommended for electrodeposition of copper underlayer on the substrate with electronegative potential