HALL-COEFFICIENT AND RESISTIVITY OF THIN POLYCRYSTALLINE CU FILMS - CONTRIBUTIONS OF BAND-STRUCTURE

Polycrystalline Cu films were produced on Cr-precoated glass substrates in the thickness range 2-40 nm at T=300 K. In situ measurements of transversal Hall coefficient and resistivity were carried out as a function of film thickness. This thickness dependence of the film structure was investigated by transmission electron microscopy and electron diffraction. While the thickness-dependent resistivity is consistent with free-electron models, the behaviour of the Hall coefficient measured at very low thicknesses (3-10 nm) is in striking qualitative contrast to the predictions of such models. This is explained by taking into account the anisotropic band structure of Cu with respect to surface and grain boundary scattering and the change in the density of states at very low thicknesses.