Ductility of thin metallic films

Pardoen, Thomas [UCL] Coulombier, Michaël [UCL] Boe, Alexandre [UCL] Safi, A. [] Brugger, Charles [UCL] Ryelandt, Sophie [UCL] Carbonnelle, Pierre [UCL] Gravier, Sébastien [UCL] Raskin, Jean-Pierre [UCL]

(eng) Depending on the loading conditions, geometry and material characteristics, the ductility of thin metallic films is controlled either by the resistance to plastic localization or by the resistance to internal damage. New on-chip tensile tests performed on submicron aluminium films show significant strain hardening capacity leading to relatively good resistance to necking, while damage occurs through void nucleation at grain boundaries followed by their growth and coalescence. These results are discussed in the light of several other studies presented in the recent literature in order to unravel the origins of the frequently reported poor ductility of thin metallic films, and the various means existing to improve it.