title: Effects of nanoscale surface roughness on the resistivity of ultrathin epitaxial copper films.
abstract: The knowledge on the influence of surface roughness and the electron-phonon (el-ph) interaction on electrical transport properties of nanoscale metal films is important from both fundamental and technological points of view. Here we report a study of the temperature dependent electron transport properties of nanoscale copper films by measuring temperature dependent electrical resistivity with thickness ranging from 4 to 500 nm. We show that the residual resistivity, which is temperature independent, can be described quantitatively using both measured vertical surface root-mean-square roughness and lateral correlation length in the nanoscale, with no adjustable parameter, by a recent quasi-classical model developed by Chatterjee and Meyerovich (2010 Phys. Rev. B 81 245409-10). We also demonstrate that the temperature dependent component of the resistivity can be described using the Bloch-Grüneisen equation with a thickness dependent el-ph coupling constant and a thickness dependent Debye temperature. We show that the increase of the el-ph coupling constant with the decrease of film thickness gives rise to an enhancement of the temperature dependent component of the resistivity.
authors: Center for Materials, Devices and Integrated Systems, and Department of Physics, Applied Physics and Astronomy, Rensselaer Polytechnic Institute, Troy, NY 12180, USA.
authors: Yukta P
authors: YP
authors: Timalsina
authors: Andrew
authors: A
authors: Horning
authors: Robert F
authors: RF
authors: Spivey
authors: Kim M
authors: KM
authors: Lewis
authors: Tung-Sheng
authors: TS
authors: Kuan
authors: Gwo-Ching
authors: GC
authors: Wang
authors: Toh-Ming
authors: TM
authors: Lu