Synergistic roles of mixed inhibitors and the application of mixed complexing ligands in copper chemical mechanical polishing
In the copper chemical mechanical polishing process, the mixed complexing ligands (glycine and disodium ethylene diamine tetraacetic acid (Na2edta)) were utilized to enhance the polishing rate and to reduce the formation of CuBTA reabsorbed molecules, and the mixed dissolution inhibitors (benzotriazole and methylbenzotriazole) were applied to reduce the surface roughness. We propose that the enhanced polishing rate is due to the formation of easier removed water-soluble Cuedta and Cuglycine complexes, and the reduced surface roughness is mainly owing to the reduction of the CuBTA reabsorbed molecules and the formation of denser surface film based on complementary space-filling adsorption mechanism for CuBTA/TTA molecules.
complexing ligand chemical mechanical polishing dissolution inhibitor