Electron scattering at transition metal surfaces
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Authors
Milosevic, Erik
Issue Date
2019-08
Type
Electronic thesis
Thesis
Thesis
Language
ENG
Keywords
Materials engineering
Alternative Title
Abstract
In situ and ex situ transport measurements of epitaxial Ru(0001) layers on Al2O3(0001) fitted with the Fuchs and Sondheimer model indicate a room-temperature electron mean free path of 6.7 ± 0.3 nm and a zero surface scattering specularity that is independent of air exposure. The measured product ρo×λ exhibits a temperature dependence, decreasing by 43% as the temperature is lowered from 295 to 77 K. This result is inconsistent with classical transport models, including the FS model, and may be related to temperature- or environment-dependent surface scattering, thickness-dependent phonon-scattering, or a more fundamental break-down of the classical transport models. Boltzmann transport simulations based on the electronic structure of Ru predict a strong anisotropy in the resistivity size effect. Simulations for transport within the basal plane of a Ru(0001) film are in reasonable agreement with experimental results, with the simulated effective mean free path being 10-33% below the experimental values. Applying the experimentally determined Ru mean free path to a polycrystalline interconnect line with a 10 nm half-pitch suggests a two times lower resistance for Ru than for a corresponding Cu line, indicating great promise for Ru as a future interconnect material.
Description
August 2019
School of Engineering
School of Engineering
Full Citation
Publisher
Rensselaer Polytechnic Institute, Troy, NY