An in-situ Study of Copper Electropolishing in Phosphoric Acid Solution

Abstract

In this work, the interface film in the Cu/H3PO4 interface was in-situ studied by tracking the time and potential evolution of the system impedance (Rs) at high-frequency. The fluctuation of Rs upon the applied potentials was confirmed by the Rs-potential plot. A copper oxide film was found formed on the copper surface during the electropolishing process by analyzing the Mott-Schottky curve. Moreover, the copper oxides film exhibited a transition of n-type semiconductor to a p-type one.