Integration and reliability of CVD Ru cap for Cu/Low-k development

Selective CVD Ru cap deposition process has been developed for BEOL Cu/low-k integration. Selectivity of CVD Ru deposition between Cu and dielectrics is investigated. Electrical performance, electromigration (EM) lifetime, voltage ramp (I-V), and time-dependent-dielectric-breakdown (TDDB) are also characterized for Cu interconnects capped with CVD Ru. This selective CVD Ru cap process is a good candidate for 22 nm and beyond technology nodes.