The adsorption behaviour of poly(ethylene glycol) (PEG), used during copper electrodeposition was investigated by using a microfluidic device for electrochemical analysis. First, the effective surface coverage ratio (θEFF) of the electrodes was obtained based on a model in which the current-density transition curve relates to the θEFF of PEG. Then, PEG concentration (c PEG) and average flow velocity (u) dependency of θEFF were evaluated. The θEFF increased with increasing c PEG and then reached saturation at 0.65 when the c PEG exceeded 200 ppm. The θEFF was independent of u; however, the time to reach saturation decreased with decreasing u.

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