The continued drive toward VLSI and three-dimensional integration places ever-increasing demands on metalization structures. New materials are needed to advance these vital technologies. The many advantages of refractory metal thin films prepared by chemical vapor deposition (CVD) including conformal step converage, high electromigration resistance and low resistivity make them attractive for gate, interconnect, contact, diffusion barrier and via plug metalizations. However, the application of CVD tungsten and molybdenum to VLSI processing has been impeded by the secondary reactions caused by the florine ligands of the elemental source reagents used in the CVD process. These reactions ultimately lead to the failure of the device. The objectives of the proposed research are the elaboration of a set of molecular design criteria for refractory metal source reagents and the identification of a novel organotungsten CVD source reagent which revolutionizes VLSI metalization. These goals will be met by applying a multidisciplinary approach in which results from film growth and fundamental decomposition studies are used to refine the molecular structure of the source reagents. The immediate commercial impact of CVD refractory metals on VLSI processing would be the advance to a new generation of metalization structures offering superior performance and stability relative to existing components.
