Evidence of enhanced electron-phonon coupling in ultrathin epitaxial copper films

Journal Article · Mon Nov 04 00:00:00 EST 2013 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4829643· OSTI ID:22254102

Shen, Xiaohan; Boruchowitz, Grant; Fu, Zhengping; Qian, Guoguang; Yamaguchi, Masashi; Wang, Gwo-Ching; Lewis, Kim M.; Lu, Toh-Ming ^[1]

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1. Center for Integrated Electronics and Department of Physics, Applied Physics and Astronomy, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States)

Electron phonon (el-ph) coupling is a fundamental quantity that controls the electron transport through a conductor. We experimentally determined the el-ph coupling strength of epitaxial copper (Cu) films ranging from 5 to 1000 nm thick using both ultra-fast, optical pump-probe reflectivity and temperature-dependent resistivity measurements. An enhancement of the el-ph coupling strength was observed when the thickness of the films was reduced to below 50 nm. We suggest that this unexpected enhancement of the el-ph coupling strength is partially responsible for the observed increase of resistivity in the films below 50 nm thick.

• OSTI ID: 22254102
• Journal Information: Applied Physics Letters, Vol. 103, Issue 19; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
COPPER
ELECTRON-PHONON COUPLING
ELECTRONS
EPITAXY
FILMS
PH VALUE
PHONONS
REFLECTIVITY
THICKNESS