Molecular Dynamics Analysis for Deformation and Fracture Behavior of Copper Thin Films

Abstract

Molecular dynamics simulation is conducted to investigate the effect of notch depth on the deformation and fracture behavior of a single crystal copper which is expected to a conductive material of micro-devices. In the stress – strain relationship, a normal stress increases with increasing applied strain. Then, the normal stress decreases rapidly. When the stress decreases, the dislocation emits from a notch root and the stacking fault is formed on the {111} plane, which is slip plane of the fcc crystalline structure. The maximum stress decreases with notch depth. The non-damaging defect size is quite small. The shear stress in the slip direction at dislocation emission is constant irrespective of the notch depth. The criterion of the dislocation emission is given by the critical value of the resolved shear stress in the sliding direction.