Synthesis of Quinacridone Derivatives and Their Application as High Performance Levelers in Electroplating (Supporting Information)

A series of quaternary ammonium salts base on quinacridone aromatic ring were synthesized using 2,9-quinacridone as the parent material, and their leveling performance were evaluated using constant-current chronoamperometry addition curves. Additionally, the adsorption abilities of the leveler molecules on copper surfaces were investigated through quantum chemical calculations and molecular dynamics simulations, and their specific adsorption sites on the copper surface were investigated by XPS, then the effect of concentration on the leveling performance was probed by through-hole plating, and the copper surface was characterized by XRD and SEM. Among four quinacridone aryl quaternary ammonium salts, DCQA-C₈-MI exhibits optimal leveling effects, serving as an excellent leveler with outstanding performance. This study expands the application scope of quinacridone aromatic heterocyclic quaternary ammonium salts and offers insights for exploring efficient organic additives for copper electrodeposition.