BEOL challenges for 14nm node and beyond

Scaling the BEOL into 14nm includes challenges in both the material selection and the integration. Metallization-induced degradation of the ULK is an issue regardless of dielectric choice, or the PVD vs. ALD selection, and options for possible recovery of characteristics are numerous. In barrier/liner/seed decisions, the integration choices play into material selection, and the deposition technique's impact upon microstructure, and hence reliability, is significant. For plating, conventional processes may not allow the high fill speeds necessary, and aspect ratio constraints are driving processes to new areas. Finally, we will also address how CPI is changing as interconnect evolves.