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

铜导线逐渐用于非常大的系统集成应用中。晶界扩散和电迁移控制着微电子器件中导线的使用寿命。通过合金化降低该速率是抑制电迁移失效的有效途径。寻找有利的合金元素需要了解GB扩散和偏析行为。该项目的主要目标是系统地研究不同元素（Ag、Bi、Fe、Ni、Ge、Cu）在非常纯净的Cu的多晶和双晶中以及在选定的Cu合金中的GB扩散。放射性示踪法与精密连续切片技术相结合，可获得GB溶质扩散的可靠实验数据。在所谓的B-和C-动力学制度的组合测量提供了一种新的和独特的方法，以获得详细的信息，在真正的稀释极限条件下的溶质偏析行为。通过Cu双晶的扩散实验，将确定偏析等温线，从而能够区分线性或非线性GB偏析。放射性示踪剂实验将结合使用分析和高分辨率透射电子显微镜溶质偏析的原子细节的研究。

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.