Process integration of CVD Cu seed using ALD Ru glue layer for sub-65nm Cu interconnect

Chemical-vapor-deposited(CVD) Cu film was successfully demonstrated as a seed layer for Cu electroplating, by using atomic-layer-deposited(ALD) Ru as a glue layer on ALD WNC barrier metal. Low via resistance of below 3/spl Omega//via was obtained in 0.13 /spl mu/m via chains, which was built in SiOC (k=2.9) intermetal dielectric. The adhesion between WNC and CVD Cu. estimated by mELT, was significantly improved by the insertion of ALD Ru and HR-XTEM analysis showed no interfacial layers at both Cu/Ru and Ru/WNC interfaces. In addition, Ru was found to promote the 2-D planar growth of CVD Cu film rather than the 3-D island growth.