Review of planarization and reliability aspects of future interconnect materials

Device linewidths are shrinking resulting:in more stringent requirements on choice of materials,, processes and designs. Current generation of memory and microprocessor designs use tungsten as the main interconnect material with aluminum being utilized in lines. It is being proposed-at the current time that copper and aluminum will be,likely candidates for the future interconnect structures. Although both metals are equally suitable as the next generation interconnect,: there still exist certain material issues relating to deposition, electromigration/reliability, and planarization that need to be addressed.