Direct measurement of grain boundary resistance in copper nanowires

As interconnect dimensions decrease, the resistivity of copper increases dramatically because of electron scattering from surfaces, impurities, and grain boundaries (GBs), and threatens to stymie continued device scaling. Here we directly measure individual GB resistances in copper nanowires with a one-to-one correspondence to the GB structure. The resistance of high symmetry coincidence GBs is then calculated using a first-principle method. GB resistance is found to differ by orders of magnitude between different types of GB, with random GBs showing an intrinsically higher resistance compared to coincidence GBs.