Title

Electron mean free path of tungsten and the electrical resistivity of epitaxial (110) tungsten films

Authors

Authors

D. Choi; C. S. Kim; D. Naveh; S. Chung; A. P. Warren; N. T. Nuhfer; M. F. Toney; K. R. Coffey;K. Barmak

Comments

Authors: contact us about adding a copy of your work at STARS@ucf.edu

Abbreviated Journal Title

Phys. Rev. B

Keywords

LASER-ABLATION DEPOSITION; FERMI-SURFACE; ATOMIC-SCALE; SAPPHIRE; ELECTROMIGRATION; INTERCONNECTS; CONDUCTIVITY; INTERFACES; NIOBIUM; METALS; Physics, Condensed Matter

Abstract

This work describes a study of the classical electrical resistivity size effect in tungsten. The important length scale for this size effect is the isotropic average electron mean free path (EMFP), which was determined to be 19.1 nm for W at 293 K by employing density functional theory. To explore the size effect experimentally, (110) oriented epitaxial W films with thicknesses ranging from 9.8 to 299.7 nm were prepared by sputter deposition onto (11 (2) over bar0) Al2O3 substrates at 520 degrees C followed by postdeposition annealing in Ar-4%H-2 at 850 degrees C. Film resistivities were measured at room temperature and at liquid He temperature. The Fuchs-Sondheimer (FS) surface scattering model with a low specularity parameter (p = 0.11) was shown to provide a good description of the film resistivity as a function of film thickness. Further, it is shown that an upper bound to the EMFP cannot be established by fitting resistivity data to the FS model, whereas a lower bound can be assessed.

Journal Title

Physical Review B

Volume

86

Issue/Number

4

Publication Date

1-1-2012

Document Type

Article

Language

English

First Page

5

WOS Identifier

WOS:000306649200009

ISSN

1098-0121

Share

COinS