Large-scale ab initio quantum transport simulation of nanosized copper interconnects: the effects of defects and quantum interferences

We present a fully ab initio direct quantum transport simulation of nano-interconnect containing a record number of atoms (similar to 5000). Various defects of the nanosized copper (Cu) interconnects, including different wire-neck shapes, twin boundaries, point defects, cobalt (Co) interstitial layers, as well as the thermal effects, are investigated with an aim to reveal the largest effects in such imperfections. We also found that the classical picture of the interconnect resistance, e.g. Matthiessen's rule, might not be valid at nanoscale, due to strong quantum interferences.