300 mm Multi Level Air Gap Integration for Edge Interconnect Technologies and Specific High Performance Applications

Air gaps were successfully integrated in a multi level metallization interconnect stack using 65 nm design rules on 300 mm wafers. The proposed approach allows a low cost integration of localized air cavities using a sacrificial material to solve via misalignment issues. Air gap integration is shown to be mechanically robust and presents excellent electrical results with high gains on RC delays. In addition, air gaps structures tested in electromigration pass the targeted lifetime criterion. This easily scalable approach can be seriously considered either in aggressive interconnect geometries or in specific applications of existing technologies for which high electrical performance is locally required.