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-FrM3
Microstructure Evolution and Interfacial Reactions in Cu-Mg Alloy Films on SiO@sub 2@

Friday, November 2, 2001, 9:00 am, Room 124

Session: ULSI Metallization & Interconnects
Presenter: M.J. Frederick, Rensselaer Polytechnic Institute
Authors: M.J. Frederick, Rensselaer Polytechnic Institute
R. Goswami, Rensselaer Polytechnic Institute
G. Ramanath, Rensselaer Polytechnic Institute
Correspondent: Click to Email
Copper is currently the preferred interconnect metal in microelectronic devices due to its high electrical conductivity and electromigration resistance. Alloying Cu with a few at.% Mg has been shown to inhibit Cu diffusion into SiO@sub 2@, promote adhesion to adjacent dielectric layers (presumably through interfacial phase formation), and increase electromigration resistance without significant decreases in conductivity. It has also been reported that Mg promotes a (002) preferred orientation. Here, we investigate mechanisms of microstructure evolution and interfacial reaction pathways in sputter-deposited Cu-Mg alloy films during annealing. We combine in situ resistivity measurements with ex-situ Rutherford backscattering spectroscopy (RBS), plan-view and cross-sectional transmission electron microscopy (TEM), and X-ray diffraction (XRD) to characterize grain size and orientation evolution, interfacial segregation and phase formation. The effects of Mg precipitation, interfacial segregation, and phase formation at the Cu/SiO@sub 2@ interface, and their influence on grain size and preferred orientation are revealed for nominal Mg supersaturations from 0 to 15 at.%. We also present preliminary results on Mg/SiO@sub 2@ structures to reveal interfacial phase formation, and epitaxial Cu-Mg(001) alloy films to the isolate effects of alloying on evolution of grain size and preferred orientation.