Regensburg 2013 – scientific programme

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MM: Fachverband Metall- und Materialphysik

MM 37: Mechanical Properties I

MM 37.5: Talk

Wednesday, March 13, 2013, 12:45–13:00, H26

Size effects of the mechanical properties of copper thin films investigated by bulge tests — •Jan Philipp Liebig, Benoit Merle, and Mathias Göken — Department of Materials Science and Engineering, Institute I, University Erlangen-Nürnberg, Germany

Plane-strain bulge testing was used to study extrinsic as well as intrinsic size effects on the mechanical behavior of thin copper films. Films of various thicknesses ranging from ~ 100 to 1000 nm were magnetron sputter deposited on freestanding silicon nitride membranes. After heat treatment under vacuum a highly twinned microstructure is obtained. Reactive ion etching was used to remove the silicon nitride layer, in order to produce free-standing Cu-membranes. Free-standing as well as passivated Cu-films were investigated in the bulge test. From the load-deflection data, equivalent uniaxial stress-strain diagrams were calculated, allowing a reliable measurement of the yield strength and work hardening coefficients of the specimens. The relative influences of the film thickness, presence of a substrate, and microstructure as characterized by Focused Ion Beam (FIB) and Electron Backscatter Diffraction (EBSD) will be discussed in the presentation.