Performance comparison and mechanism analysis between new nontoxic Losartan and traditional corrosion inhibitor BTA in cobalt chemical mechanical polishing

Cobalt (Co) as an emerging interconnect solution for integrated circuits (ICs) is prone to corrosion during chemical mechanical polishing (CMP). However, traditional inhibitors are toxic and inefficient, making the development of non-toxic and highly efficient inhibitors urgent. This study reports for the first time that the antihypertensive drug Losartan exhibits excellent performance in balancing corrosion protection and polishing efficiency in Co CMP processes. Polishing experiments and Atomic Force Microscope (AFM) tests reveal that Losartan enhances the material removal rate (MRR) while improving surface integrity relative to Benztriazole (BTA). Electrochemical tests, adsorption isotherms, X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM) confirm that Losartan's comprehensive performance as a new organic inhibitor surpasses that of BTA. Energy dispersive spectroscopy (EDS) results indicate that Losartan forms a dense protective adsorption film on the Co surface. Density functional theory (DFT) reveals Losartan’s multisite adsorption on the Co surface through various sites of nitrogen, oxygen, and chlorine atoms. It theoretically explains that its corrosion inhibition effect is superior to BTA. This study provides reference for choosing green and effective corrosion inhibitor for Co CMP.