Effects of dielectric liners on TDDB lifetime of a Cu/ low-k interconnect

Thin films of silicon nitride (SiN) or silicon carbonitride (SiCN) were deposited as liners at metal-1 in a dual level metal Cu/organosilicate glass interconnect. Breakdown field and time dependent dielectric breakdown lifetime testing of comb/serpent test structures with SiN or SiCN liners showed improvements in performance, relative to a baseline no liner split. Two dimensional electric field simulations demonstrated that the dielectric liner significantly reduced the electric field at the Cu/OSG/etch stop interface.