Electrically testable CMP characterization vehicle for DFM, process transfer, and process development

An electrically testable two-mask characterization vehicle for damascene copper CMP is presented. Using electrical test to extract metal thickness allows for characterization of multiple lots, wafers, and sites across the wafers, enabling both DFM and process development applications. Layout experiments were designed to study the effect of same-layer width and density on metal thickness, as well as previous layer density. Results are presented demonstrating the capability and limitations of using this approach to characterize and model metal thickness variations introduced by the CMP process.