Chemical mechanical polishing for copper films in integrated circuit wiring layers using an advanced slurry

In the chemical mechanical polishing process of integrated circuits (IC) copper (Cu) wiring layer, it is difficult to balance between material removal rate (RR) and surface quality. To solve this problem, a novel slurry composed of dodecylbenzene sulfonic acid (DBSA), 2-aminobenzimidazole (2-ABI) and multi-walled carbon nanotubes (MWCNTs) was proposed. The Cu surface roughness of 0.63nm with RR of 5290Å/min had been achieved. Polishing, electrochemical experiments and molecular dynamics simulations revealed that when DBSA: 2-ABI=1: 4, the strongest inhibition effect was obtained. Quantum chemical calculations showed that the strong interaction force of hydrogen bonding between 2-ABI and DBSA greatly enhanced the inhibition efficiency. Surface morphology testing showed that the addition of MWCNTs could effectively reduce scratches.