Due to surface and disorder scattering, resistivity of metal wires keeps increasing with shrinking dimensions, which severely impacts the performance of highly scaled integrated circuits. Here we explore a new class of materials – topological semimetals – as an alternative solution. We demonstrate that, via conduction of the protected surface electronic states, resistivity in topological semimetals reduces with decreasing feature size down to ~ nm scale, even in the presence of defects and grain-boundary scattering. This novel scaling behavior sharply contrasts that of conventional metals, such as Cu, and topological insulators. In this talk, we will first present first-principles-based electrical transport calculations of a Si-CMOS compatible topological semimetal CoSi and a prototypical Weyl semimetal NbAs. We will then report experimental evidence for surface-dominated transport in CoSi thin films, showing resistivity below that of the bulk single-crystals. Our proof-of-principle study demonstrates the potential of topological semimetal as beyond Cu interconnect materials.