Pattern Density Effects on the Chemical Mechanical Planarization of an Interlevel Polymer Dielectric

Chemical Mechanical Planarization is quickly becoming a standard in microelectronical processing. CMP can decrease the depth of focus constraints in photolithography, resolve topography issues for multilevel interconnects, improve metal step coverage, and be used as an alternative etch process. The recent break-through in the copper damascene process has invoked a large number of studies focused on the planarization of oxides and metals. The research has proven beneficial for other applications where oxides are used as an interlevel dielectric material It has also shown the need for further studies in the polishing of other dielectric materials. The purpose of this experiment was to study the effects that pattern density had on both the polish rate of the polymer and changes the pattern density made to the improvement of planarization. Interactions, if any, between the pattern density and the other factors were also to be studied.