Investigation of the inhibition properties and mechanism of salicylaldoxime for copper corrosion via experimental and theoretical methods

During the chemical mechanical planarization (CMP) process, copper (Cu) is susceptible to excessive corrosion, which can lead to an increase in surface roughness of the wafer. In severe cases, this excessive corrosion can result in short circuits, open circuits, and even global interconnect failures. Therefore, this study investigates the inhibitory properties of salicylaldoxime (SA) as a corrosion inhibitor for Cu corrosion through systematic experimental measurements and theoretical calculations. The research findings demonstrate that both SA and SA− exhibit strong molecular activity. They can adsorb onto the surface of Cu through chemical and physical interactions in a parallel or slightly tilted manner, forming inhibitor films that effectively shield against the corrosion caused by corrosive particles. The corrosion inhibition performance of SA is enhanced with increasing concentration. Moreover, SA can react with Cu2+ to form insoluble complexes. It is speculated that these complexes may deposit on the surface of Cu, serving as complementary inhibitor films. These new discoveries provide novel insights and robust support for a better understanding of the corrosion inhibition mechanism of SA and its potential in subsequent practical applications in Cu CMP.