Paper TF-TuM5
Ruthenium and Ruthenium Oxide Thin Films prepared by Atomic Vapor Deposition for MIM Applications

Tuesday, October 21, 2008, 9:20 am, Room 302

As outlined in the International Technology Roadmap for Semiconductors (ITRS), new electrode and high-k materials have to be introduced to replace polysilicon and silicon dioxide, to allow continued scaling of further device technologies. In this study ruthenium and its metallic oxide RuO2 have been examined as possible candidates for MIM (metal-insulator-metal) capacitors. Ruthenium has a low bulk electrical resistivity of 7 microOhmcm. Ruthenium and ruthenium oxide also have very good diffusion barrier properties. We have deposited ruthenium and ruthenium oxide films by AVD (atomic vapor deposition), a pulsed MOCVD (metal organic vapor deposition) method. This method allows to combine features of ALD (atomic layer deposition), such as atomic layer control with the high deposition rate of MOCVD. The electrode films with a typical thickness of 10 nm were deposited on hafnium oxide dielectrics and silicon dioxide as reference. Physical characterization was done by Transmission Electron Microscopy (TEM), Ellipsometry, Atomic Force Microscopy (AFM), and X-Ray Reflectometry (XRR). Near bulk densities of Ru and RuO2 of 12 and 7 g/cm3 have been obtained. For Ru on hafnium oxide a sheet resistance of 10 Ohm/square was achieved. Advanced MIM capacitors were fabricated and characterizes by I vs. U and C vs. U measurements. Even after 5 months storage in ambient conditions the structures showed almost no change in breakdown characteristics. Results from physical and electrical measurements will be presented and correlated. This work was performed within the SEA-NET project funded within the 6th Framework Program of the European Commission, SEA-NET Contract no.: 027982. See www.sea-net.info.