A 7 level metallization with Cu damascene process using newly developed abrasive free polishing

A 7 level metallization including 4 levels of Cu metallization by the damascene technique is successfully developed using newly developed abrasive free polishing (AFP). This new AFP process reduced erosion and dishing, defect density, and improved TDDB lifetime of dielectric layers. We also improved corrosion resistance for Cu wiring. This process was used to fabricate a metallization structure of a new-cache memory chip consisting of 9-Mb 0.6-ns SRAMs and 200-K 25 ps ECL gate arrays. And this Cu metallization suppresses parasitic capacitance of interconnects and reduces clock wiring delay by 30%.