Direct CMP process with advanced ELK for 45 nm half pitch interconnects

We have improved ELK film so that it is suitable for the processes used in fabricating Cu interconnects without using a dielectric protection layer for CMP, the so called “direct CMP process”. The depth profile of the pore size in the film was successfully controlled to prevent water absorption during the CMP process with a limited k-value increase in the film. The line-to-line dielectric breakdown voltage and the time dependent dielectric breakdown lifetime at the 45 nm spacing for the advanced ELK interconnects without the DPL were significantly improved.