The effect of structural properties of benzo derivative on the inhibition performance for copper corrosion in alkaline medium: Experimental and theoretical investigations

Abstract

As the most commonly used multilayer interconnect metal material of integrated circuits, copper corrosion inhibition is a key technical problem in chemical mechanical polishing (CMP). Many organic compounds represented by benzo derivatives have been widely studied as copper corrosion inhibitors in CMP slurry. In this study, the adsorption performance and inhibition mechanism of three benzo derivatives (BI, BTA, and MBI) on copper in glycine medium under alkaline conditions were studied by experimental and theoretical methods to explore the influence of the molecular structure of the inhibitors on the corrosion inhibition performance. The electrochemical results and gravimetric methods show that the three organic molecules are mixed inhibitors, and the order of inhibition efficiency for copper is BTA > MBI > BI. The increase of contact angle on the copper surface confirmed the adsorption of hydrophobic inhibitors on the copper surface. Atomic force microscope and scanning electron microscope tests further confirmed this. X-ray photoelectron spectroscopy reveals that the three inhibitors can form inhibitor adsorption film on the copper surface, indicating that they have excellent corrosion inhibition properties. In addition, the electronic properties and reactive sites for the interaction with the copper surface were identified by quantum chemical calculation. Molecular dynamics simulation was used to investigate the most stable configuration of the inhibitor molecules on the Cu (111) surface in aqueous medium and to explain the results of molecular-level experiments.