Electrochemical–mechanical polishing application: Monitoring of electrochemical copper removal from current–voltage characteristics in HNO3 electrolyte

Recently, electrochemical–mechanical polishing (ECMP) has been suggested as an alternative to the conventional chemical–mechanical polishing (CMP) process. In ECMP process, copper (Cu) ions are electrochemically dissolved by applying an anodic potential to the Cu surface in an electrolyte. In this paper, the voltage-activated electrochemical reactions of Cu for ECMP application were investigated with different concentration of HNO3 electrolyte. The electrochemical characteristics of Cu such as active, passive, transient and trans-passive state were evaluated from its current–voltage (I–V) curve obtained by linear sweep voltammetry (LSV) and cyclic voltammetry (CV) method. The proposed mechanism and analyses were a good methodology in finding suitable electrochemical process parameter for ECMP application.