A hydrodynamic and kinematic analysis of chemical–mechanical planarization mechanism in double sided polisher

Abstract

In this study, a hydrodynamic and kinematic analysis of the double sided chemical–mechanical planarization (CMP) mechanism is discussed. The workpieces are disk substrates with a hole at the center. The hydrodynamic results show that the disk surface has a positive fluid pressure zone and a negative pressure zone. The positive pressure zone squeezes out the used slurry and the negative pressure zone sucks in the fresh slurry. The high pressurized slurry with abrasive particles has a significant interaction with the disk surface and removes the material. The self rotation of the disks inside the carriers is beneficial for the uniformity and global planarization of the disks. The kinematic analysis results show that a transient center of the carriers exists and the velocity magnitude and direction change abruptly at this position. It should be avoided on the disk surface, because such a transient center is a halt point which may cause defects on the disk surface. The velocity at the carrier center is steady, but the velocity at the carrier edge has a larger oscillation with a higher average number. The critical waviness and surface integrity can be optimized via the kinematic parameters by the abrasive particle trajectories on the disk surface.