An ultra-thin ALD TaN barrier for high-performance Cu interconnects

To meet the ITRS line resistance specifications for Cu interconnects at the 65 nm device node, the barrier thickness must be minimized. An ultra-thin amorphous ALD TaN barrier has been proposed that shows to be an effective barrier at 10Å thickness. Physical characterization of composition and barrier property has been presented along with electrical integration data. Line resistance and via resistance data shows that lower interconnect resistance can be obtained with ALD barriers. Interconnect reliability with the integration of ALD barriers along with stress migration data have also been discussed and presented.