Surface Interaction Effect and Mechanism of Methionine Derivatives as Novel Inhibitors for Alkaline Copper CMP: Insights from Molecular Simulation and Experimental Analysis

To prevent excessive corrosion caused by the slurry in the copper (Cu) chemical mechanical polishing (CMP) process, a corrosion inhibitor is normally required. In this study, the methionine (Met) derivative FMOC-L-Methionine (Fmoc-Met-OH) was explored as a corrosion inhibitor for Cu film CMP in weak alkaline conditions (pH = 8.5). A comprehensive evaluation was conducted to confirm the efficiency of Fmoc-Met-OH as a corrosion inhibitor, combining experiments and theoretical calculations. The results showed that Fmoc-Met-OH could effectively inhibit the corrosion of Cu, with a high inhibition efficiency ( IE ) of 78.26% while maintaining a high removal rate ( RR ) of 5703 Å min −1 , a low static etch rate ( SER ) of 676 Å min −1 , and a low surface root mean square deviation ( Sq ) of 1.41 nm. Simultaneously, the results of X-ray photoelectron spectroscopy (XPS) tests and electrochemical analysis confirm that Fmoc-Met-OH molecules can form a dense and ordered adsorption film on the Cu surface. According to the density functional theory (DFT) calculations and molecular dynamics (MD) simulation, it was verified that Fmoc-Met-OH exhibited strong chemical adsorption on Cu substrates, as evidenced by the high binding energy ( E Binding ) value, low energy gap (Δ E ), and radial distribution function (RDF) analysis. The findings provided theoretical evidence of the better inhibition effectiveness of Fmoc-Met-OH at a molecular or atomic level. The methionine derivative FMOC-L-Methionine (Fmoc-Met-OH) is firstly selected as a new green corrosion inhibitor for Cu film CMP in weak alkaline conditions (pH=8.5) to reduce Cu removal rate ( RR ). Fmoc-Met-OH has an excellent inhibition efficiency of 78.26% at 0.43 wt%. AFM and SEM studies show the Fmoc-Met-OH protected the Cu. The Fmoc-Met-OH adsorption behavior were simulated by MD. The inhibition layer is adsorbed on the Cu surface by S-Cu/C-Cu bond to prevent further corrosion.