Degradation of inhibitor in alkaline cleaning solution for post-Cu CMP cleaning

In this current work, the degradation of the commercial alkaline cleaning solution for post-Cu chemical mechanical planarization (CMP) cleaning process was systemically investigated. According to the results of electrochemical measurements and X-ray photoelectron spectroscopy, the degradation of the commercial alkaline cleaning solution originated from the oxidation of the commercial amino-group corrosion inhibitor in it, thus resulting in the formation of CuO film from native Cu2O film. Eventually, we proposed that the commercial alkaline cleaning solution should be sealed in an inert-gas blanket during chemical drum preservation to avoid oxygen exposure in the atmosphere, and therefore the production of the scratch defects due to the formed CuO layer was significantly reduced.