Grain Boundary Diffusion und Grain Boundary Segregation in Cu and Cu-Based Alloys

• Applicant: Professor Dr. Guido Schmitz
• Subject Area: Thermodynamics and Kinetics as well as Properties of Phases and Microstructure of Materials ; Synthesis and Properties of Functional Materials
• Term: from 2004 to 2010
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5431168

Copper conductor lines are progressively used in very large system integration applications. Grain boundary (GB) diffusion and electromigration controls the service life of the conductor lines in microelectronic devices. The reduction of this rate by allowing is alloying is an effective way for inhibiting electromigration failure. The search of favorable alloying elements requires knowledge of GB diffusion and segregation behavior. Systematic investigation of GB diffusion of different elements (Ag, Bi, Fe, Ni, Ge, Cu) in poly- and bicrystals of very pure Cu and in selected Cu alloys is the main goal of the project. Application of the radiotracer method in combination with precise serial sectioning technique will result in reliable experimental data on GB solute diffusion. The combination of measurements in the so-called B- and C-kinetic regimes provides a new and unique method to obtain detailed information on the solute segregation behavior in true dilute limit conditions. By diffusion experiments with Cu bicrystals segregation isotherms will be determined that enable to distinguish between linear or non-linear GB segregation. The radiotracer experiments will be combined with a study of atomistic details of solute segregation using analytical and high-resolution transmission electron microscopy.

• DFG Programme: Research Grants
• Participating Person: Professor Dr. Sergiy Divinski