The Effect of Glycine and Benzotriazole on Corrosion and Polishing Properties of Cobalt in Acid Slurry

Cobalt has caused much interest as an adhesion layer for copper metallization in the next generation interconnect technology. This work investigates the effects of glycine and BTA on corrosion and polishing properties of Co in the acid slurry. The potentiodynamic polarization measurement results show that glycine can increase the corrosion rate of Co. In the solution containing H2O2, adding glycine can make the Co surface smoother. In the slurry without H2O2, BTA shows good inhibition effect on Co corrosion. BTA can adsorb on the Co surface through physisorption and chemisorption, and obeys Langmuir absorption isotherm. In the acid slurry with H2O2, BTA will react with Co2+ ions and form insoluble networked nanoparticles ([Co(II)(BTA)2·H2O]n) on the Co surface, and induce reduction of the removal rate and static etch rate of Co.