Static and dynamic mechanical behavior of micron-sized Cu structures

Copper structures in microelectronic devices have to fulfill two important requirements, a high electrical and thermal conductivity. However, the lifetime is determined by the static and dynamic mechanical properties of the Cu structures.

Increasing the mechanical strength of Cu by adding alloying elements negatively affects the thermal and electrical conductivity and should be avoided. Thus, optimizing the grain size in the micron-sized Cu structures is the concept investigated in this study.

The applied methodology includes micro-mechanical tensile tests at room temperature and elevated temperatures, and cyclic tension-tension loading. The mechanical findings are correlated with microstructural observations including SEM-EBSD, and atom probe tomography to study the grain boundary chemistry.

This research topic was carried out in collaboration with KAI (Villach), Infineon (Villach, Regensburg), U Leoben and U Rouen.