Analysis of Current-Potential Hysteresis during Electrodeposition of Copper with Additives

摘要: Two models are described for cyclic voltammetry during electrodeposition of copper from an acid sulfate bath containing the additives polyethylene glycol (PEG), chloride ions and mercapto-1-propanesulfonate (MPSA). The same may be used superfilling cavities fabrication on-chip metallization. Experimental current-potential scans show a characteristic hysteresis in solutions with all three additives, which demonstrates presence both activated inhibited kinetics. Both assume that deposition is by PEG-chloride adsorbed surface complex, as established previously. One model further hypothesizes PEG incorporated into grain boundaries at fractional coverage found on external surface. second neglects incorporation, but assumes adsorbing MPSA directly displaces predict quantitatively similar to experiments, without use of'fitting parameters. competitive adsorption favored because, unlike incorporation model, it yields realistic predictions carbon sulfur concentrations deposit.