Mechanical strength lowering in submicron Cu thin films by moderate DC current

This letter reports an experimental investigation into the direct current (DC) induced reduction in the yield strength of 60 ∼ 700-nm-thick Cu films. Results show that the larger the current density and the thinner the film, the greater the reduction when the film thickness is below about 340 nm. This reduction could be described on the basis of dislocation buckling, which, caused by the electron wind of the current flow, induces an increase in the dislocation length and a decrease in the critical stress for multiplying the dislocation.