Influence of microstructure on the conduction mechanisms in discontinuous metal films on dielectric substrates

Electrical properties of discontinuous Pt, Cu and Al films were examined. The temperature dependencies of resistance were measured in vacuo in situ for examined films. Structural examinations of the films were conducted by means of electron microscope. Making use of the micrographs and the measured data the dependencies log(R) versus coverage coefficient are presented for selected temperature. To explain the experimental results, especially in the percolation threshold interval, the resistances of discontinuous Pt, Cu and Al films were calculated using a computer method which includes such mechanisms as a substrate conduction, metal conduction, thermally activated tunnelling and quantum tunnelling. Using the computer method, the relationship between log(R) and coverage coefficient were calculated. It was found the qualitative agreement between measured and calculated data. The conduction mechanisms in discontinuous Pt, Cu and Al films are proposed in the different ranges of coverage coefficient. (C) 2004 Elsevier Ltd. All rights reserved.