Contact resistance measurement of bonded copper interconnects for three-dimensional integration technology

A novel test structure for contact resistance measurement of bonded copper interconnects in three-dimensional integration technology is proposed and fabricated. This test structure requires a simple fabrication process and eliminates the possibility of measurement errors due to misalignment during bonding. Specific contact resistances of bonding interfaces with different interconnect sizes of approximately 10/sup -8/ /spl Omega/-cm/sup 2/ are measured. A reduction in specific contact resistance is obtained by longer anneal time. The specific contact resistance of bonded interconnects with longer anneal time does not change with interconnect sizes.