IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Electronics Friday Sessions
       Session EL-FrM

Paper EL-FrM7
Conductivity Issues with Cu at sub-100 nm Dimensions

Friday, November 2, 2001, 10:20 am, Room 124

Session: ULSI Metallization & Interconnects
Presenter: S.M. Rossnagel, IBM T.J. Watson Research Center
Authors: S.M. Rossnagel, IBM T.J. Watson Research Center
C. Inoki, SUNY-Albany
T.S. Kuan, SUNY-Albany
Correspondent: Click to Email
At thicknesses or dimensions at or well below 100 nm, Cu resistivity increases significantly. The primary issues are the so-called size effect (scattering from surfaces), grain boundary scattering and orientation effects, surface roughness, and impurities. In addition, diffusion barriers will have a negative effect due to displacement of Cu layers. Measurements on polycrystalline and single crystal Cu films and some features down to 20 nm show resistivity increases as-high or higher than predicted, indicating diffuse electron scattering at surfaces. Varying the surfaces of the Cu, either the roughness or the composition of overlayers, shows some positive effects at limiting the large effect of the scattering. In addition, the size effects of other materials, such as Au and Al, indicate that at sub-40 nm dimensions, Cu may no longer be desireable.