Calculated Resistances of Single Grain Boundaries in Copper

Abstract

As the width of a copper interconnect approaches an electron's mean free path length, its resistivity increases dramatically--a real problem in nanoelectronics. A main cause is electron scattering at grain boundaries (GBs), yet the specific resistivity of a $s\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}n\phantom{\rule{0}{0ex}}g\phantom{\rule{0}{0ex}}l\phantom{\rule{0}{0ex}}e$ GB remains unclear in general. The authors develop a fully atomistic first-principles technique to calculate this property, and the result for a coherent twin GB matches experiment well. They furthermore predict the resistivities of other GBs for which experimental data are lacking, and suggest a way to improve interconnect conductivity.