Excellent electro/stress-migration-resistance surface-silicide passivated giant-grain Cu-Mg alloy interconnect technology for giga scale integration (GSI)

Completely (100)-oriented Cu-Mg films having giant grains (typical grain sizes of ~100 μm) were obtained by depositing Cu-Mg films on SiO₂ followed by thermal annealing at 450°C. The Cu-Mg film exhibits a room temperature resistivity of 1.81 μΩ·cm. And this interconnect exhibits 3 times larger migration resistance than the giant-grain Cu interconnect. Furthermore, by employing the self-aligned surface-silicide passivation to the Cu-Mg interconnect, the migration resistance is greatly enhanced. It exhibits two orders of magnitude larger migration resistance than non-passivated giant-grain Cu interconnect at a room temperature