Excellent electro/stress-migration-resistance giant-grain copper interconnect technology for high-performance power devices

Abstract

By using an ultra-clean low-energy ion bombardment process, we have succeeded in forming Cu interconnects having giant grains (typical grain sizes of /spl sim/100 /spl mu/m). The giant-grain Cu interconnects exhibit three-orders of magnitude larger migration resistance than conventional Al-alloy interconnects. Moreover, by exposing the giant-grain Cu interconnects in SiH/sub 4/ ambient at 200/spl deg/C, Si selective deposition on Cu interconnect surface is successfully carried out. The surface-silicide passivated giant-grain Cu interconnects exhibit four orders of magnitude larger resistance against electromigration and stressmigration than conventional Al-alloy interconnects.