CMP Composition Dual Corrosion Inhibitors Copper Erosion

The patent combines two different corrosion inhibitors (N-heterocyclic compound and prop-2-ynyloxy-substituted alcohol) in a single CMP composition. This composite approach creates synergistic effects where the N-heterocyclic compound provides primary corrosion protection through chelation, while the prop-2-ynyloxy-substituted alcohol enhances protection and reduces static etch rates, achieving superior polishing performance that neither inhibitor could achieve alone.

The patent optimizes specific parameter ranges for the dual-inhibitor system: N-heterocyclic compound at 0.01-5 wt% and prop-2-ynyloxy-substituted alcohol at 0.1-5 wt%, with pH controlled at 3-7. These parameter changes maximize the synergistic effect between the two inhibitors, achieving low static etch rates and high material removal rates simultaneously.

The patent achieves high material removal rates (superior to conventional compositions) while maintaining excellent surface quality by optimizing the dual-inhibitor system. The N-heterocyclic compound controls corrosion during polishing, and the prop-2-ynyloxy-substituted alcohol further suppresses static etch rates, enabling aggressive material removal without the usual trade-off of increased erosion or dishing.

The synergistic combination of two corrosion inhibitors creates a composite protection mechanism that allows high productivity. The N-heterocyclic compound provides immediate corrosion inhibition during mechanical removal, while the prop-2-ynyloxy-substituted alcohol provides sustained protection against static etching, enabling high material removal rates without compromising surface quality.

The patent employs a composite corrosion inhibition strategy using two chemically distinct inhibitors. The N-heterocyclic compound (such as triazole or imidazole derivatives) provides primary protection through strong metal chelation, while the prop-2-ynyloxy-substituted alcohol provides secondary protection and specifically targets static etch rate reduction. This composite approach achieves superior control over dishing and erosion that single inhibitors cannot accomplish.

The patent applies different inhibitors for different protective functions: the N-heterocyclic compound primarily addresses active corrosion during polishing, while the prop-2-ynyloxy-substituted alcohol specifically targets static etch rates that cause dishing and erosion. This localized functional assignment optimizes surface quality by addressing different degradation mechanisms with specialized inhibitors.