Effects of current density on micro-mechanical properties of electrodeposited gold were evaluated by micro compression test. Three gold films were electrodeposited at 20 A/m(2), 50 A/m(2) and 100 A/m(2). The average grain sizes were analyzed by XRD. The specimens used in the micro-compression test were micro-pillars having a square cross-section and the long-side parallel to the Au/electrolyte interface fabricated by focused ion beam. Three sizes of the cross-section were prepared, which were 8 mu m x 8 mu m, 10 mu m x 10 mu m and 15 mu m x 15 mu m, and the height was kept at twice of one side of the cross-section. The micro-pillars all showed high yield strengths ranged from 400 MPa to 650 MPa, because of the micro-scale sample size by the sample size effect and the nano scale average grain size by the grain boundary strengthening. In addition, the largest sample size effect was observed in micro-pillars fabricated from the gold film electrodeposited at 100 A/m(2).
NSTL
Elsevier