The material removal mechanisms for Cu electrochemical mechanical planarization (ECMP) including 5-Methyl-1H-Benzotriazole (TTA), hydroxyethylidenedi phosphoric acid (HEDP), and tribasic ammonium citrate (TAC) were investigated by electrochemical techniques, X-ray photoelectron spectrometer (XPS) analysis, and polishing of Cu-coated blanket wafers. The experimental results show that the main factor affecting the thickness of the oxide layer formed during ECMP process is the applied potential. This understanding is beneficial for optimization of ECMP processes.
