The synergistic effect between a triblock copolymer and chloride ions in Cu electrodeposition into microvias

Interactions between a triblock copolymer, commercially named Pluronic L64, and chloride ions (Cl^-) was found efficient for Cu electrodeposition in microvia filling process. Cyclic voltammetry (CV) curves clearly showed the synergistic effect between L64 and Cl^- to inhibit copper electrodeposition. CV stripping measurements further suggested that the possible synergistic effect was dependent on the concentrations of L64 and Cl ^-. With a fixed L64 concentration (≥ 7.5 ppm), there was a proper Cl^- concentration to achieve the maximum synergistic effect. Haring cell experiments confirmed that the results obtained from CV stripping tests can be used for guiding microvia filling experiments.