Influence of microstructure and internal stress on the mechanical behavior of electroplated gold freestanding thin films

¹ CNES, 18 av edouard Belin Bpi1414 31401 Toulouse Cedex 9, France
² NOVAMEMS, c/o CNES, DCT/AQ/LE, bpi 1414, 18 Av. Edouard Belin, 31401 Toulouse, France
³ Université de Lyon, INSA-Lyon, INL, CNRS UMR 5270, Villeurbanne, F-69621, France
⁴ LGP-ENIT, 47 Av. d’Azereix, BP 1629, 65016 Tarbes CEDEX, France
⁵ INTESENS, 10 Avenue de l’Europe 31520 Ramonville, France

^a e-mail: julien.martegoutte@cnes.fr

Abstract

Mechanical properties of freestanding electroplated gold thin films were studied in relationship to their geometrical and microstructural properties. Three different techniques of characterization were used: nanoindentation, bulge tests and microtensile tests. Results were compared to literature and also discussed according to physical phenomena related to the elaboration process of the specimens like seed layer exodiffusion or internal stress state. The observed plasticity and failure mechanisms were found to be in good agreement with the literature and are consistent with the microstructure. The measured Young’s modulus is slightly higher than expected, and SIMS analysis is exploited to explain such a high value.