Resistance of Thin Metal Films Grown under a Longitudinal Electric Field

Abstract

Thin‐film samples of platinum, silver, and gold were prepared in pairs on glass substrates by evaporation in a vacuum of 10⁻⁶−10⁻⁷ Torr, one sample of the pair under an electric field (usually 40 V/cm, either dc or 500‐Hz square wave) applied along the substrate surface and the other sample under no field. Sample resistances were measured in the vacuum at temperatures ranging from roughly 0 °C to 4 °K. The resistances of the samples deposited under a field were almost invariably lower, sometimes by orders of magnitude, than those of the corresponding samples grown under no field. Electron micrographs show that the former samples had elongated and interconnected grains while the latter samples had roundish and more islolated grains. The data are discussed in terms of a simple model based on the notion that the film particles polarize, stretch, and even coalesce under the applied electric field before they solidify.