Physical and electrical characterization of ALCVD TM TiN and WN x C y used as a copper diffusion barrier in dual damascene backend structures(08.2)

The application of copper diffusion barrier films deposited by atomic layer deposition (ALD, ALCVD™) on functional multilevel, dual damascene structures is in its infancy. In this study, two different ALD barrier films (TiN and WNC) were evaluated to determine how they affected the electrical properties of two-metal layer, dual damascene copper structures built in SiO2. In addition, bulk properties of each film were evaluated. It was found that ALD films show feasibility of functioning electrically in fully integrated interconnect structures as well as acting as a copper diffusion barrier and copper adhesion layer.