Electrochemical Impedance Spectroscopy (EIS) Analysis of BTA Removal by TMAH during Post Cu CMP Cleaning Process

摘要

In the present study, the efficiency of TMAH in removing BTA organic layer from Cu surface is evaluated through electrochemical impedance spectroscopy studies. As the conventional EIS measurements could not be applied in situ to study the cleaning system, a modified EIS experimental procedure is adopted in the present work. The impedance data is validated by Kramers Kronig transform (KKT) and modeled by electrical equivalent circuit (EEC) model. Contact angle measurements were also conducted to complement the studies. The results show that a minimum concentration of 0.5 wt % TMAH is required for complete removal of BTA from the Cu surface.