Abstract
Role of via-filling additives for Copper electrodeposition is discussed. Addition of Cl- causes macro steps. PEG forms about 10nm granular molecules and absorbs preferentially on the edge of these macro steps. This adsorption of PEG inhibits the macro step growth. About 10nm fine copper crystals form with an addition of JGB and SPS. With an addition of Cl-and PEG, the current-overpotential curves shift towards to the cathode side, which inhibits copper electrodeposition. With JGB in addition to Cl-and PEG, the curve shift towards to the cathode side with an increase in rotation speed of rotating disk electrode. This means that PEG molecules become diffusion control with JGB. We observe less adsorption of PEG molecules at via bottom if compared to that at via outside. PEG adsorption inhibits copper electrodeposition at via outside and preferentially fill the via bottom.
