Mechanical Behavior of Electrodeposited Copper Film at Elevated Temperatures

The temperature dependence of the strength of a thin copper electrodeposit has been measured, by microtensile testing, from room temperature to 150 °C. The ultimate tensile strength decreased from around 240 MPa at room temperature to just above 200 MPa at 150 °C. The yield strength followed a similar trend. Elongation to failure increased slightly with temperature. The Young’s modulus, as measured by the unload-load slope, was well below the values expected based on averaging single-crystal elastic constants at all test temperatures. The effect of strain rate on strength at room temperature, using a range of over a decade, was low, with a weak trend upward.

A Study of Gaseous and Organic Inclusions in Copper Electrodeposit by Transmission Electron Microscopy

It was recently shown (1) that gaseous and organic inclusions in electrodeposits can he detected "by transmission electron microscopy (TEM) using a through-focus imaging technique. In this study, we have investigated the sites for incorporation of inclusions and their spacial distribution in copper electrodeposit by TEM.A copper film was electrodeposited on an annealed OFHC copper sheet in a sulfate electrolyte (200 g/l CuSo4-5H2O, 50 g/l H2So4) containing 5 M Mol./l O-phenanthroline as an organic additive. Plating was carried out at room temperature and at a current density of 5 MA/cm2.In order to detect gaseous and organic inclusions, all copper deposits were examined in overfocussed as well as underfocussed conditions. In each case, stereo-pairs(2) were obtained. Figures 1 and 2 show stereo-pairs of the deposited copper film taken in overfocussed and underfocussed conditions, respectively.