Corrosion Inhibition and the Synergistic Effect of Three Different Inhibitors on Copper Surface

Abstract

Copper(Cu) has been an interconnect material widely used in giant-large scale integrated circuits (GLSI). Corrosion inhibitor is a key factor to ensure global planarization of Cu in the CMP slurry. In this paper, three selected inhibitors BTA(Benzotriazole), TAZ(1,2,4-triazole), and MBO( 2-Benzoxazolethione) were investigated inhibition behaviors and synergy on the Cu surface. The results show that they are all effective Cu inhibitors in alkaline solutions. MBO loses its ability in H 2 O 2 , but BTA and TAZ do not. The calculated synergistic parameters of BTA/TAZ is 0.1763, XPS and UV–Via experiments show that the antagonism between them is caused by two competitive reactions due to the similar adsorption mechanism: one is the competition for the adsorption site on the surface, and the other is the competition of copper ions that affects the formation of Cu(I)-BTA. The calculated synergistic parameter of BTA/MBO is 1.7763, the synergy between them is obvious.