CoWP metal caps for reliable 32 nm 1X Cu interconnects in porous ULK (k=2.4)

CoWP metal cap layers with good reliability (EM, SM, TDDB) for 32 nm thinwire interconnect structures in low-k (k=2.7) and porous ultralow-k (ULK) dielectrics (k=2.4) are demonstrated. Relative to structures not having CoWP, substantial EM benefits, comparable yield, and TDDB behavior are observed with the inclusion of CoWP metal caps layers. © 2010 Materials Research Society.