Two-Component Corrosion Inhibitor Working Mechanism on Cu Surface

Cu CMP slurries are typically composed of abrasive particles, oxidants, etchants and corrosion inhibitors. The Cu surface is planarized by the CMP process via a repetitive process of oxidation by oxidants, followed by the corrosion inhibitor absorption on the Cu surface and the polish behavior generated by the etchant and abrasive particles. Benzotriazole (BTA) is a commonly used corrosion inhibitor in Cu CMP slurries to effectively prevent Cu from being etched by forming a passivation layer of Cu-BTA. However, benzotriazole exhibits poor solubility in water that can contribute to increased organic residue defect on the wafer surface. In this paper, we describe how we added Component A to be a corrosion inhibitor that was linked with benzotriazole by H-bonding to protect the Cu surface. We investigated the working mechanism for controlling Cu removal rate.