An analytical model of multiple ILD thickness variation induced by interaction of layout pattern and CMP process

In this paper, an analytical model for chemical mechanical polishing (CMP) is described. This model relates the physical parameters of the CMP process to the in-die variation of interlayer dielectric (ILD) in multilevel metal processes. The physical parameters considered in this model include the de posited no profile, deformation of the polishing pad and the hydrodynamic p ressure of slurry flow. Model parameters are adjusted based on the first LL D layer and then applied to the upper no layers. Comparison of simulated re sults with sample data is performed at the die level of a state-of-the-art microprocessor.