Development of the post-chemical mechanical polishing cleaner suppressing galvanic corrosion between copper and the Co barrier metal

To develop the post Cu-CMP cleaner, we investigate galvanic corrosion of Co as used barrier metal by electrochemical measurements. To elucidate relationship between cleaner composition and galvanic corrosion, corrosion potential is investigated by Tafel plot and corrosion current is measured by Liner Sweep Voltammetry (LSV). As results, LSV indicates variation of galvanic corrosion caused by chelator and inhibitor. Furthermore, result of LSV shows well agreement with etching rate of Co wafer which electrically connected with Cu wafer.