Electrical properties and TDDB performance of Cu interconnects using ALD Ta(Al)N barrier and Ru liner for 7nm node and beyond

We have integrated ALD barrier and Ru liner for novel interconnect integration and have evaluated electrical properties and time dependent dielectric breakdown (TDDB). RC and via resistance were reduced by the ALD barrier, and particularly it was confirmed that TDDB performance can be improved by using ALD TaAlN with an ultrathin film. Accordingly, ALD TaAlN barrier and CVD Ru liner are attractive barrier/liner combination for next generation interconnect integration schemes.