Modeling the effect of bumpy abrasive particles on chemical mechanical polishing

In this study, the effect of course surface roughness of abrasive particles on the removal rate in chemical mechanical polishing is analyzed. The mechanical contact theory is used and the relationship between the polishing rate and properties of pad, wafer, and abrasive particle is studied. Particular attention is given to the case where abrasives are compact bumpy particles and the pad is soft. It is found that the polishing rate depends on the size of abrasive particle bumps. The penetration depth of bumpy particles is larger than that of the spherical particles of the same diameter; the removal rate by the abrasive wear mechanism for bumpy particles, however, is less than the corresponding smooth spherical particles. (C) 2002 The Electrochemical Society.