Role of Dispersant Agent on Scratch Reduction during Copper Barrier Chemical Mechanical Planarization

Abstract

The chemical mechanical planarization (CMP) has been one of the major manufacturing process to provide global and local surface planarizations in integrated circuits (IC) fabrications. Defects such as micro-scratches generated during CMP can lead to severe circuit failure, which affects yield. In the present work, ethoxylated decylalchohol (EDA) was used as dispersant agent to prevent the particles agglomeration to reduce scratches. Firstly, the effect of EDA on particle size distribution (PSD) of the slurry was investigated by dynamic light scattering (DLS) method. Then the effect of EDA on large particle counts (LPC) was studied through a dual sensor single particle optical sensing (SPOS) analysis method. The wetting ability of slurries as a function of EDA concentration was also studied. Finally, the defect scan tool and scanning electron microscope (SEM) reviewer were used to identify the scratch defects. The results show that the addition of EDA into the slurry can enhance the dispersity of colloidal silica abrasives and significantly reduce the number of large particles in the slurry, the SEM review results show that the scratch counts remarkably decreases with EDA concentration increasing. It can be demonstrated that the EDA can effectively reduce the scratch counts.

Surface Forces in Chemical Mechanical Planarization and Semiconductor Wafer Cleaning Systems

“…3) Defect reduction -surfactants are used to decrease defects during planarization process; reduce scratches, minimize slurry particle adhesion, minimize particle contamination form material which is being polished, etc.) [12][13].…”

Methods and Mechanistic Analysis of Improving the Dispersion of Nano Silica Colloidal Particles in Chemical Mechanical Polishing Slurries

“…Khushnumaasghar et al [15] found that SDS (sodium dodecyl sulfate) improved the dispersion of slurry and reduced the surface roughness of GaN substrate after polishing. Yanleili et al [4] found that non-ionic ethoxylated decylalchohol (EDA) can be used as a dispersing agent to reduce scratches in copper interconnection polishing. There are many ways to improve the dispersion of slurry, and surfactants show great potential.…”

“…The interaction between colloidal particles will lead to the aggregation of colloidal particles due to irresistible factors, including: 1. The particles in the colloid collide with each other spontaneously due to Brownian motion, and some of them gather together over the repulsion barrier [4]. 2.…”

Corrosion Inhibition and the Synergistic Effect of Three Different Inhibitors on Copper Surface

“…The research hotspots also focus on the role and mechanism of chemical reactions. [5][6][7][8][9] As Cu is easily over-corroded in the CMP process, the corrosion inhibitor is added to the slurries to control the excessive corrosion on the Cu surface. A large number of studies have shown that corrosion inhibitors form an inhibitor film with sulfur or nitrogen atoms adsorb on Cu surface through physical adsorption and chemical adsorption that hinders the contact between Cu and slurry.…”