Electrodeposition of copper in the presence of additives mixture that is typically used in "bottom-up'' fill of sub-micrometer vias and trenches on semiconductor wafers is analyzed. The time-dependent additives interactions, accounting for their transport and adsorption kinetics, are incorporated in a via-fill model. Transient polarization measurements provide the adsorption time constants for polyethylene glycol (PEG) and bis(3-sulfopropyl) disulfide (SPS). Experiments indicate that the fast PEG adsorption on the electrode is diffusion controlled, while the slow SPS adsorption is controlled by the adsorption kinetics. The results are applied to a transport-kinetics model that provides the additives distribution inside a via. It is noted that the PEG diffusion to the via bottom is extremely slow due to the PEG adsorption on the sidewalls. The role of SPS in the bottom-up fill is characterized by simulating the transport within the via through analogous transport to a flat rotating disk electrode. It is observed that SPS is essential for maintaining fast deposition at the via bottom by preventing PEG adsorption. The critical necessity for a three-additive system comprised of chloride ions, PEG, and SPS is explained, and process parameters essential for bottom-up fill are identified. (C) 2004 The Electrochemical Society.