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-Copper cavities with a thin niobium film -as used in the large electron positron collider LEP -would be also attractive for future linear colliders, provided the decrease of the Q-value with the accelerating gradient could be reduced. We aim at extracting the important parameters that govern this decrease. The dependence on the RF frequency is studied by exciting 500 MHz and 1500 MHz cavities in different modes. In addition we combined RF measurements for two 1500 MHz cavities of different RF performance with microscopic tests (AFM, TEM) on samples cut out of the same cavities. Their micro-structural characterization in plan-view allows to extract the grain size and the defect densities.

Microstructural characterization (Focused Ion Beam and Transmission ElectronMicroscopy imaging) was performed on cross-sections of contacts in thick Electro Chemical Deposition copper metallization of System In Package Integrated Circuits. It was shown that the lower growth rate of ECD-Cu in the AlSiCu -barrier Ti -PVD-Cu -ECD-Cu layer stacking is related to a local higher resistivity induced by the presence of a great number of almost planar grain boundaries in the PVD-Cu layer, which are perpendicular to the growth axis. This morphology is a consequence of the almost heteroepitaxial growth of Ti layer on AlSiCu layer.