First principles-based screening method for resistivity scaling of anisotropic metals

Abstract

The resistivity scaling of metals is a crucial factor for further downscaling of interconnects in nanoelectronic devices that affects signal delay, heat production, and energy consumption. Here, we present a screening method for metals with highly anisotropic band structures near the Fermi level with the aim to select promising materials in terms of their electronic transport properties and their resistivity scaling at the nanoscale. For this, we consider a temperature-dependent transport tensor, based on band structures obtained from first principles. This transport tensor allows for a straightforward comparison between different anisotropic metals in nanostructures with different lattice orientations. By evaluating the temperature dependence of the tensor components, we also find strong deviations from the zero-temperature transport properties at standard operating temperature conditions around room temperature.

Properties of ultrathin molybdenum films for interconnect applications

“…8a) led to a mean free path of λ = 11.2 nm, in agreement with the results in [13]. We remark that the resistivity of bulk cubic Mo is anisotropic as is the mean free path in this framework [53]. The model further requires the knowledge of the film thickness dependence of the linear intercept length between grain boundaries (related to the grain size [54]).…”