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

By using an ultra-clean low-energy ion bombardment process, we have succeeded in forming Cu interconnects having giant grains (typical grain sizes of ~100 μm). 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 SiH₄ ambient at 200°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