Surface Roughness and Surface-Induced Resistivity of Thin Gold Films On Mica
- PDF / 137,807 Bytes
- 6 Pages / 612 x 792 pts (letter) Page_size
- 4 Downloads / 201 Views
SURFACE ROUGHNESS AND SURFACE-INDUCED RESISTIVITY OF THIN GOLD FILMS ON MICA. Raúl C. Munoz *#, German Kremer*** and Luis Moraga*** Guillermo Vidal** and Claudio Arenas** *Departamento de Física, **Departamento de Ingeniería Eléctrica Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile Blanco Encalada 2008. Casilla 487-3. Santiago 6511226, Chile. ***Departamento de Física, Facultad de Ciencias, Universidad de Chile Las Palmeras 3425. Santiago, Chile # corresponding author: Departamento de Física. Facultad de Ciencias Físicas y Matemáticas. Universidad de Chile. Blanco Encalada 2008. Casilla 487-3. Santiago 6511226, Chile. email: [email protected]. Telephone: 56-2-696-0148; FAX: 56-2-696-7359.
ABSTRACT. We report measurements of the surface topography of a 70 nm gold film deposited on mica preheated to 300 oC in UHV performed with a Scanning Tunneling Microscope (STM). From these measurements we determine the rms roughness amplitude and the lateral correlation length characterizing the average height-height autocorrelation function on a nanometric scale.We also report a method of analyzing thin film resistivity data that departs sharply from the traditional method of parameter fitting. This method allows the determination of the resistivity and mean free path characterizing the bulk from the measured thin film resistivity by means of a new iteration procedure, that uses as input data the roughness parameters experimentally determined with the STM and any of the available quantum transport theories, without adjustable parameters. We examine the resistivity data reported by Sambles et al. [Philos. Trans. R. Soc. London, Ser. A304, 365 (1982)] for gold films deposited on mica under similar substrate temperature and similar speed of evaporation. The remarkable outcome is that any of the quantum transport theories available, describe approximately both the temperature as well as the thickness dependence of the resistivity data without any adjustable parameter. Another surprise is that the parameters characterizing the bulk—assumed to be independent of thickness for many years—turn out to be thickness dependent. INTRODUCTION. One of the fundamental problems in solid state physics that has attracted the attention of researchers for over 60 years, relates to the effect of electron-surface scattering on the transport properties of thin metallic and semiconducting films. A central issue is how the surface of the structure affects its electrical transport properties, when one or more of the dimensions characterizing the structure are comparable to or smaller than the mean free path of the charge carriers, what is known as ‘size effects’. The theoretical work concerning size effects focused for many decades on the Fuchs-Sondheimer (FS) theory, in which the
R5.6.1
electron motion is modeled by a Boltzmann Transport Equation (BTE) and the effect of the rough surface is incorporated into the boundary conditions that must be satisfied by the electron distribution function obeying a BTE via a specularity paramete
Data Loading...
