A Wafer-Scale Particle Augmented Mixed Lubrication Modeling Approach for Chemical Mechanical Polishing

The mechanical or tribological action in CMP involves hydrodynamic lubrication, solid-solid contact and wear, primarily resulting from hard particles removing material by abrasion. Present work introduces a much faster version of the particle augmented mixed lubrication (PAML) modeling approach, previously introduced by Terrell and Higgs [1], in the form of a framework called PAML-lite. With this introduction of this model, the PAML approach can now be applied to the full-scale wafer-pad interface. Results from this work include the evolution of the hydrodynamic fluid pressure, contact stress, and finally the material removal at the local and wafer scales. Comparisons with existing CMP experiments have been made and the results are favorable.