Electromigration mechanisms in Cu lines

Summary form only given. The electromigration in 0.15 /spl mu/m to 10 /spl mu/m wide and 0.3 /spl mu/m thick Cu lines deposited by physical vapor deposition has been investigated using both resistance and edge displacement techniques in the sample temperature range 225/spl deg/C-405/spl deg/C. For wide polycrystalline lines (>1 /spl mu/m), the dominant diffusion mechanism is a mixture of grain boundary and surface diffusion, while in narrow lines (< 1 /spl mu/m) the dominant mechanism is surface transport. The electromigration lifetime of fine Cu lines is estimated.