Cu electromigration improvement by adhesion promotion treatment (APT)

A new process to promote adhesion between the SiC diffusion barrier and Cu was developed to achieve significant improvement in electromigration of the Cu interconnect without sacrificing RC delay, line-to-line leakage, breakdown voltage and time-dependent-dielectric-breakdown. An in-situ treatment of the wafer surface inserted between the sequential processes of Cu pretreatment and SiC deposition increased the Cu/SiC interfacial adhesion by more than 30%. Electrical and physical characterization data is presented that demonstrates the improvement in reliability metrics of the interconnect using the newly developed process, while limiting the RC change to <; 1%.