Ultralow Electron-Surface Scattering in Nanoscale Metals Leveraging Fermi Surface Anisotropy

Abstract

Increasing resistivity of metal wires with reducing nanoscale dimensions is a major performance bottleneck of semiconductor computing technologies. We show that metals with suitably anisotropic Fermi velocity distributions can strongly suppress electron scattering by surfaces and outperform isotropic conductors such as copper in nanoscale wires. We derive a corresponding descriptor for the resistivity scaling of anisotropic conductors, screen thousands of metals using first-principles calculations of this descriptor and identify the most promising materials for nanoscale interconnects. Previously-proposed layered conductors such as MAX phases and delafossites show promise in thin films, but not in narrow wires due to increased scattering from side walls. We find that certain intermetallics (notably CoSn) and borides (such as YCo${}_3$B${}_2$) with one-dimensionally anisotropic Fermi velocities are most promising for narrow wires. Combined with first-principles electron-phonon scattering predictions, we show that the proposed materials exhibit 2-3x lower resistivity than copper at 5 nm wire dimensions.

11 pages, 5 figures, 1 table; SI within source archive

References in corpus (4)

• JDFTx: software for joint density-functional theory
• Fantastic flat bands and where to find them: The CoSn-type compounds
• On the metallic conductivity of the delafossites PdCoO2 and PtCoO2
• Ab initio screening of metallic MAX ceramics for advanced interconnect applications

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• First-principles Prediction of Carrier Mobility in Semiconductor Nanowires Based on the Spatially Dependent Boltzmann Transport Equation
• Accelerated Discovery of Topological Conductors for Nanoscale Interconnects