Corrosion inhibition mechanisms of triazole derivatives on copper chemical mechanical polishing: Combined experiment and DFT study

The impact of triazole derivative groups on corrosion inhibition performance of copper (Cu) film is studied by using 3-amino-1,2,4-triazole-5-carboxylicacid (ATA-O), 1H-1,2,4-triazole-3,5-diamine (ATA-N) and 3-amino-5-mercapto-1,2,4-triazole (ATA-S) as environment-friendly inhibitors. Electrochemical analysis showed that anti-corrosion passivation layer is formed on Cu surface after adding inhibitors with high inhibition efficiency of 54 %, 87 % and 98 % respectively, and improve the surface quality which is verified by atomic force microscope (AFM) and scanning electron microscopy (SEM) tests. Such results are consisted with static etch experiments. The mechanism of corrosion inhibition was revealed by theoretical calculation, which prove that the lone electron pair in empty orbitals of the O, N, S atoms on inhibitors hybridize with the Cu-d orbital to form covalent bonds and enhance the adsorption passivation action. Such study dissects the reasons for the potent inhibitory effect of triazole derivatives at the atomic level, and provides new method for efficient selection of inhibitors.