Effects of kinematic variables on nonuniformity in chemical mechanical planarization

The effects of kinematic variables on the nonuniformity of the wafer in che mical mechanical planarization (CMP) are investigated. The nonuniform amoun t of material removal is calculated by the velocity integral and the experi mental nonuniformity is measured. This analysis becomes more important as t he wafer size increases and the requirement for within-wafer nonuniformity is more rigorous. The effects of the rotational and translational speeds an d carrier eccentricity are discussed. The significance of velocity uniformi ty is proved based on the analysis and experiment. The wafer size possesses great importance in the nonuniformity. Large eccentricity is useful, while the translation speed of the carrier plays a minor role in view of kinemat ics. The analysis provides a guide to the design of a process window in CMP . The experimental results support the analytical approach. (C) 2000 Elsevi er Science Ltd. All rights reserved.