Cosputtered Cu/Ti Bonded Interconnects With a Self-Formed Adhesion Layer for Three-Dimensional Integration Applications

A novel 3-D bonding technology with cosputtered copper and titanium as bonding material is proposed and investigated based on the diffusion mechanism of cosputtered metal during bonding. This technology features a self-formed adhesion layer for Cu metal layers and interconnects. In addition, cosputtered Cu/Ti bonding exhibits good electrical performance as well as high resistance to multiple current stressing. With the advantages of fabrication efficiency and reliable bond quality, cosputtered Cu/Ti bonding technology presents the potential to be applied in 3-D integration.