CMP Fill Synthesis: A Survey of Recent Studies

We survey recent research and practice in the area of chemical-mechanical polishing (CMP) fill synthesis, in terms of both problem formulations and solution approaches. We review the CMP as the planarization technique of choice for multilevel very large-scale integration metallization processes. Post-CMP wafer topography varies according to pattern density. We review density-analysis methods and density-control objectives that are used in today's fill-synthesis algorithms. In addition, we discuss the concept of design-driven fill synthesis that seeks to optimize CMP fill with respect to objectives beyond mere density uniformity. Design-driven fill synthesis minimizes the impact of CMP fill on design performance and parametric yield while still satisfying the density criteria that are motivated by manufacturing models. We conclude with a discussion of where CMP fill synthesis may be naturally integrated within future design and manufacturing flows.