Enhancing CMP Performance of Micro-Structured Pad Patterns: CFD Simulations and Experimental Evaluations

This study explored the impact of micropattern designs on slurry dynamics in chemical mechanical planarization (CMP), focusing on pressure distribution, slurry flow and streamlines, abrasive residence time, and drag force. Using computational fluid dynamics (CFD) simulations, we examined how different pad patterns, including circle, triangle, square, ellipse, and square-circle, affect slurry behavior. It was found that the elliptical patterns caused the largest pressure drops due to their shape and arrangement, thus affecting material removal rates. Velocity analyses revealed that mean residence times and slurry flow velocities vary for different patterns, impacting the effectiveness of material removal. The results for the square-circle pattern showed a balanced slurry interaction, optimizing MRR by ensuring uniform slurry distribution and minimizing recirculation. The simulated drag forces exerted by the slurry on the pad patterns were correlated with the oxide removal rates. Particle tracking further illustrated how pattern design affects abrasive particle distribution, which is crucial for uniform polishing. The study identified the square-circle pattern as the optimal pattern design for TEOS film removal, highlighting the importance of pad pattern geometry in enhancing CMP efficiency. The presented simulation study highlighted the significance of micropattern design in advancing semiconductor manufacturing, offering insights for future pad design innovations.