Validation of constant mean free path and relaxation time approximations for metal resistivity: explicit treatment of electron-phonon interactions

Abstract

The figure of merit $\rho \lambda$ the product of resistivity and mean free path (MFP) evaluated from first-principles calculations, is widely adopted to screen promising interconnect metals with high electrical conductivity at ultranarrow dimensions. However, the $\rho \lambda$ has been calculated without addressing the validity of the assumption that the MFP is independent of the wavevector $\mathbf{k}$. Here, we assess the validity of the constant MFP approximation, by estimating the $\mathbf{k}$-dependent MFPs for (an)isotropic elemental metals, with explicit treatment of electron-phonon interactions. Additionally, we verify the validity of the constant relaxation time approximation (CRTA) for resistivity calculations. We show that both the constant MFP approximation and CRTA are reasonable even for highly anisotropic Fermi surfaces. Our results support the practical use of those approximations in transport studies, where explicit electron-phonon calculations are not feasible.

References in corpus (12)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Phonons and related properties of extended systems from density-functional perturbation theory
• Advanced capabilities for materials modelling with Quantum ESPRESSO
• Optimized norm-conserving Vanderbilt pseudopotentials
• Maximally localized Wannier functions: Theory and applications
• The PseudoDojo: Training and grading a 85 element optimized norm-conserving pseudopotential table
• First-principles calculations of charge carrier mobility and conductivity in bulk semiconductors and two-dimensional materials
• Perturbo: a software package for ab initio electron-phonon interactions, charge transport and ultrafast dynamics
• Thickness dependence of the resistivity of Platinum group metal thin films
• Finite Size Effects in Highly Scaled Ruthenium Interconnects
• Ultralow Electron-Surface Scattering in Nanoscale Metals Leveraging Fermi Surface Anisotropy
• Ab initio screening of metallic MAX ceramics for advanced interconnect applications

Cited by in corpus (1)

• Cobalt Binary Compounds for Advanced Interconnect Materials