A 3D Numerical Study of the Polishing Behavior during an Oxide Chemical Mechanical Planarization Process

Abstract

The slurry fluid motion, abrasive particle motion, and roles of groove patterns on the pads are numerically investigated in 2D and 3D geometries. The simulation results were analyzed in terms of experimental removal rate and WIWNU (within wafer non-uniformity) for ILD (inter level dielectric) CMP process. Numerical investigations revealed that the grooves in the pad behave as the uniform distributor of abrasive particles and enhance the removal rate by increasing shear stress. Higher removal rate and desirable uniformity are numerically and experimentally observed at the pad with grooves. Numerical analysis results matched very well with the experimental results and are useful for understanding the polishing mechanism and local physics.